Easy Programming Challenges – Hirevue Classic Recruiter Help Center

Add Number Series
Difficulty: Easy	Test Cases: 6	Published: 2012-11-06
Summary Add a series of numbers from 1 through n
Description Write a program that, given an integer, sums all the numbers from 1 through that integer (both inclusive). Do not include in your sum any of the intermediate numbers (1 and n inclusive) that are divisible by 5 or 7.
Input Your program should read lines from standard input. Each line contains a positive integer.
Output For each line of input, print to standard output the sum of the numbers from 1 through n, disregarding those divisible by 5 and 7. Print out each result on a new line.

Add Number Series II
Difficulty: Easy	Test Cases: 8	Published: 2019-05-31
Summary Add a series of numbers from 1 through n with a rule
Description Write a program that, given an integer N, sums all the whole numbers from 1 through N (both inclusive). Do not include in your sum any of the intermediate values (1 and N inclusive) that are divisible by 3 or 7.
Input Your program should read lines from standard input. Each line contains a positive integer.
Output For each line of input, print to standard output the sum of the integers from 1 through N, ignoring those divisible by 3 or 7. Print out each result on a new line.

Alter Case
Difficulty: Easy	Test Cases: 6	Published: 2012-11-02
Summary Camel case a given sentence
Description Write a program that, given an input sentence, alternates the case of every alphabetic character, starting with uppercase. Spaces and non-alphabetical characters should be added to the final output as is, i.e. they should not be taken into account when alternating between upper/lowercase.
Input Your program should read lines from standard input. Each line contains a sentence. Assume all characters are ASCII.
Output For each sentence from standard input, print to standard output the sentence such that the first character is uppercase, the next character is lowercase and so on.

Armstrong Numbers
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Determine if a number is an armstrong number.
Description An Armstrong number is an n-digit number that is equal to the sum of the nth powers of its digits. Determine if the input numbers are Armstrong numbers.
Input Your program should read lines from standard input. Each line has a positive integer.
Output Print out True if the number is an Armstrong number, or False if not.

Asteroid Mining
Difficulty: Easy	Test Cases: 12	Published: 2019-08-07
Summary Compute the minimum number of days required to mine a certain amount of mineral
Description You are starting an asteroid mining mission with a single harvester robot. That robot is capable of mining one gram of mineral per day. It also has the ability to clone itself by constructing another harvester robot. That new robot becomes available for use the next day and can be involved in the mining process or can be used to construct yet another robot. Each day you will decide what you want each robot in your fleet to do. They can either mine one gram of mineral or spend the day constructing another robot. Write a program to compute a minimum number of days required to mine n grams of mineral. Note that you can mine more mineral than required. Just ensure that you spent the minimum possible number of days to have the necessary amount of mineral mined.
Input A single integer number n, which is the number of grams of mineral to be mined. The value of n will be between 1 and 1000000 (inclusive). For example: 9
Output A single integer, the minimum number of days required to mine n grams of mineral. For example: 5

Avocado Prices
Difficulty: Easy	Test Cases: 12	Published: 2020-03-06
Summary Calculate summary statistics for a variable in a dataset
Description Consider a dataset containing the distribution of avocado prices across various regions over a specific time period. Given that dataset, calculate the following summary statistics: min - the minimum of the values max - the maximum of the values mean - the mean of the values std - a corrected sample standard deviation, that uses denominator n - 1
Input A dataset in CSV format with the avocado prices to summarize. The dataset has the following columns: date - the date of the observation price - the price of a single avocado region - the name of the region For example: date,price,region 2015-07-19,1.08,Louisville 2015-08-16,1.05,RichmondNorfolk 2015-04-05,1.1,Orlando 2015-07-26,1.12,GrandRapids 2015-05-31,1.1,Atlanta
Output Print the summary statistics as four real numbers. Print each value on a separate line in the following order: min max mean std Each real value must be rounded to the required number of digits after the decimal point: min and max - 2 digits mean - 3 digits std - 4 digits Keep all trailing zeros in the result. Rounding should be done to the nearest value using round half to even rule: if the number falls midway, it is rounded to the nearest value with an even least significant digit. For example, rounding to 3 digits after the decimal point 1.0135 becomes 1.014, as does 1.0145. This is the default behavior of the round function in Python, R, etc. For example: 1.05 1.12 1.090 0.0265

Beautiful Strings
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Facebook Hacker Cup 2013 problem: Determine the beauty of strings.
Description When John was a little kid he didn't have much to do. There was no internet, no Facebook, and no programs to hack on. So he did the only thing he could... he evaluated the beauty of strings in a quest to discover the most beautiful string in the world. Given a string s, little Johnny defined the beauty of the string as the sum of the beauty of the letters in it. The beauty of each letter is an integer between 1 and 26, inclusive, and no two letters have the same beauty. Johnny doesn't care about whether letters are uppercase or lowercase, so that doesn't affect the beauty of a letter. (Uppercase 'F' is exactly as beautiful as lowercase 'f', for example.) You're a student writing a report on the youth of this famous hacker. You found the string that Johnny considered most beautiful. What is the maximum possible beauty of this string?
Input Your program should read lines from standard input. Each line is a string.
Output Print out the maximum beauty for the string.

Binary Addition
Difficulty: Easy	Test Cases: 5	Published: 2012-11-01
Summary Binary numbers addition
Description Write a program that, given two binary numbers represented as strings, prints their sum in binary. The binary strings are comma separated, two per line. The final answer should not have any leading zeroes. In case the answer is zero, just print one zero i.e. 0
Input Your program should read lines from standard input. Each line contains two binary strings, separated by a comma and no spaces.
Output For each pair of binary numbers print to standard output their binary sum, one per line.

Binary Coded Decimal - Encoding
Difficulty: Easy	Test Cases: 7	Published: 2019-07-15
Summary Convert an integer number to the binary coded decimal (BCD) code
Description Imagine that you are prototyping an electronic device based on the Arduino platform and you are using a seven-segment display to show numeric values. To reduce the number of used digital outputs of the microcontroller, the display board is connected to the main board through the integrated circuit of the decoder, which converts binary coded decimal (BCD) values to signals for the seven-segment display. So, to show any number on the display you need to set the required BCD code on the microcontroller's outputs. Write a program to convert an integer number represented as a string to a BCD code required for the display. In the BCD code, every decimal digit is encoded with its four-bit binary value. Encoding all digits of the decimal number and concatenating the resulting codes into one string you will get a resulting BCD code. A space is used to separate digits in the BCD code and make it more readable. For example, a number 173 will be encoded to BCD as 0001 0111 0011.
Input Each line has a string representing a non-negative integer number. For example: 5 17
Output Each line contains a BCD code of the number at the corresponding line of the input. Codes of the decimal digits are separated from each other with a space. For example: 0101 0001 0111

Bit Positions
Difficulty: Easy	Test Cases: 5	Published: 2012-10-08
Summary Bits in position x, y are same or different.
Description Given integers n, p1, and p2, determine if the bits of n in position p1 and p2 are the same. Positions p1, p2 are 1 based with 1 being the least significant bit.
Input Your program should read lines of text from standard input. Each line will contain the integers n, p1, and p2, separated by commas.
Output For each line of input, print "true" to standard output if the bits are the same, or "false" otherwise, one per line.

Cached Out
Difficulty: Easy	Test Cases: 5	Published: 2019-04-02
Summary Implement a simple Cache that enforces Uniqueness
Description Build an in-memory string cache that guarantees each entry is unique. This cache requires the following functions: Add Adds the supplied string to the cache and returns "True" if it was added or "False" if it already exists Get Returns the requested string if it exists in the cache or "NULL" if it does not exist in cache Has Returns "True" or "False" to indicate if the string is in the cache or not Remove Deletes the requested string from the cache and returns "True" if it was removed or "False" if it did not exist Reset Empties the cache of all entries and returns the number of entries Try to implement this cache in a way that will have high read performance across a potentially large set.
Input Each line of input will have two parts separated with a pipe character: Function Name String Value For example: Add\|Dog Get\|Dog Remove\|Dog Has\|Dog The Reset function is an exception. It will only have the Function Name as input.
Output One line of output based on the function called by each line of input. For example: True Dog True False

Calculate Distance
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Calculate a distance between two points
Description You have (x, y) coordinates for 2 points and need to find the distance between them.
Input Your program should read lines from standard input. Each line contains two space-delimited coordinate pairs. All x and y values are integers between -100 and 100.
Output Print the distance between the two points. You do not need to round the results you receive.

Camel Case Machine
Difficulty: Easy	Test Cases: 6	Published: 2019-04-02
Summary String formatting test to fit the Camel Case standard
Description Reformat a series of strings into Camel Case by returning the fragments from input as a single "sentence". For example, consider the following input: Camel Case LOOKS like ThIs Would result in: camelCase looksLikeThis
Input A series of strings with one fragment on each line of input. All characters will be from the ASCII character set.
Output A single line with the inputs assembled in Camel Case

Capitalize Words 2
Difficulty: Easy	Test Cases: 12	Published: 2022-06-30
Summary Capitalize words in a sentence
Description Write a program which, given a sentence, puts the first letter of each word into upper case.
Input Your program should read lines from standard input. Each line has a space-delimited sequence of words. Each word contains English letters, digits, and underscores. For example: Hello world
Output Print the capitalized words. For example: Hello World

Character Counting
Difficulty: Easy	Test Cases: 6	Published: 2012-11-07
Summary Count the frequency of characters in a string
Description Write a program that, given a string, outputs a new string that contains each character in the original string exactly one time, followed by the frequency of occurrences of that character in the original string, and in alphabetical order.
Input Your program should read lines from standard input. Each line contains a string. The string will consist of ASCII characters and no spaces. Ignore case when considering a character. e.g. 'a' and 'A' are to be interpreted to be the same. When printing out the character, it should always be in lowercase and the characters should be alphabetically sorted.
Output Print to standard output the new string comprised of each character followed by its frequency. Print out each result on a new line.

Common Suffix
Difficulty: Easy	Test Cases: 8	Published: 2012-10-08
Summary Common Suffix of two strings
Description Write a program that finds the longest common suffix between two strings. If there is no common suffix, print the string NULL. Assume that the strings only contain ASCII characters.
Input Your program should read lines from standard input. Each line contains two strings separated by a comma. Assume that each line will have exactly one comma.
Output For each pair of input strings, print to standard output the longest common suffix between them.

Compare Numbers
Difficulty: Easy	Test Cases: 10	Published: 2013-12-23
Summary Given two integers A and B, print out the symbol that accurately compares A to B (either >, <, or =).
Description Little Tommy is in kindergarten on the first day of class. His teacher has taught him about inequalities today, and he is learning how to draw crocodiles to represent them. When there are two numbers, A and B, there are three options: 1. If A is greater than B, then draw '>'. The crocodile's mouth is pointed toward the bigger number, A. 2. If A is less than B, then draw '<'. The crocodile faces B. 3. If A is equal to B, draw '='. The crocodile is confused and keeps its mouth shut. Unfortunately, Tommy does not like to do his homework, and has bribed you to write a program to do it for him.
Input The input consists of two integers A and B on a line, separated by a space. \|A,B\| < 2^63.
Output Print a line containing the appropriate symbol that describes the relationship between the numbers.

Compare Points
Difficulty: Easy	Test Cases: 10	Published: 2013-12-23
Summary Given two (x, y) points A and B, determine which cardinal direction B is from A.
Description Bob's hiking club is lost in the mountains on the way to a scenic overlook. Fortunately, Bob has a GPS device, so that he can see the coordinates where the group is currently at. The GPS gives the current X/Y coordinates as O, P, and the scenic overlook is located at Q, R. Bob now just needs to tell the group which way to go so they can get to the overlook in time for s'mores.
Input The input consists of four integers O, P, Q, R on a line, separated by spaces. \|O,P,Q,R\| < 10000.
Output Print a line containing one of the following: N NE E SE S SW W NW here if the coordinates Q,R are (respectively) north, northeast, east, southeast, south, southwest, west, northwest, or already at ("here") the coordinates O,P.

Compressed Sequence
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Compress a sequence using a simple algorithm
Description Assume that someone dictates you a sequence of numbers and you need to write it down. For brevity, he dictates it as follows: first says the number of consecutive identical numbers and then says the number itself. E.g. The sequence 1 1 3 3 3 2 2 2 2 14 14 14 11 11 11 2 will be dictated as "Two ones, three threes, four twos, three fourteens, three elevens, one two", so you will write down the sequence 2 1 3 3 4 2 3 14 3 11 1 2. The challenge is to write the program which compresses the given sequence using this approach.
Input Your program should read lines from standard input. Each line is a sequence of L integers, where each integer is N, separated by a whitespace. N is in range [0, 99]. L is in range [1, 400].
Output For each test case, produce a single line of output containing a compressed sequence of numbers separated by a single space char.

Corporate Ladder
Difficulty: Easy	Test Cases: 7	Published: 2019-04-02
Summary Assemble individual pairs in a hierarchy
Description A company wants to track change in their organization by knowing how many levels exist between any two employees. This number will help them know who is being promoted and who is not. For example: If Susan reports to John and John reports to Amy. Then, there are 2 level between Susan and Amy. Write a program that will count how many levels exist between any two names in a hierarchy of employees. The program must read a list of name pairs that represent an employee and their manager. HINT: The two names to compare may be in different parts of the organizational tree and not have a direct managerial line.
Input The first line of input will be a pair of names to compare. All subsequent lines will be employee/manager pairs. The company's complete hierarchy will be included so no incomplete trees will exist. For example: Susan/Amy Susan/John John/Amy
Output The number of levels between the pair requested, including the top manager's level. In the example above, the Output should be: 2

Custom Merge
Difficulty: Easy	Test Cases: 4	Published: 2019-04-18
Summary Merge two sorted arrays with a special requirement
Description Write a program that, given two sorted arrays of integers, will produce a sorted array containing all elements of both. There's a special requirement: Sorting must consider all even numbers to be greater than odd numbers. Note that the size of array can be large. Try to find an efficient solution with linear running time.
Input Two comma-separated arrays of integers. The two arrays are separated by a semicolon. For example: 1,5,7,4;3,7,2
Output The merged and sorted array formatted as a comma-separated series of values. The sorting must treat all even numbers as greater than odd numbers. For example: 1,3,5,7,7,2,4

Dash Insert
Difficulty: Easy	Test Cases: 6	Published: 2012-11-05
Summary Inserting characters between digits
Description Write a program that, given an integer, inserts a '*' between adjacent digits that are both even and a '-' between adjacent digits that are both odd. Zero should not be considered even or odd.
Input Your program should read lines from standard input. Each line contains a positive integer.
Output For each line from standard input, print to standard output the input string with '*' and '-' properly inserted as described above, one string per line.

Data Converter - CSV to JSON
Difficulty: Easy	Test Cases: 4	Published: 2019-04-02
Summary Export a Tabular Data Set to JSON
Description Read a tabular data set from input and write it out in JSON. For example: Purchase Date,Item Name,Amount,Currency 2019-01-07,Pizza,18.00,USD 2019-01-07,Ice Cream,6.00,USD 2019-01-08,Dozen Eggs,4.00,USD
Input A CSV-formatted series of records with one record on each line of input. The first line of input will have the column names for the data set. No escape characters or special handling for values containing commas or quotes will be used.
Output A standard JSON-formatted response in the RFC 7159 format with two spaces per indent. The first item will be the field headers from the CSV.

Decimal To Negabinary
Difficulty: Easy	Test Cases: 7	Published: 2019-10-04
Summary Print the negabinary representation of a decimal number
Description Given a decimal (base 10) integer, print out its negabinary representation (base -2). Conversion of the integer value can be done through repeated division by -2. At each division operation, a non-negative and minimal remainder must be chosen. For example: - 3 / -2 = 2 remainder 1 -3 / -2 = 1 remainder - 1 Both results above are valid, but the first of them must be selected for the conversion since it is the least, non-negative remainder.
Input Each line of the input contains a single integer value (base 10).
Output For each integer, print its negabinary representation. Print one per line, with no leading zeros.

Download Time
Difficulty: Easy	Test Cases: 12	Published: 2020-03-06
Summary Calculate the estimated time to download a file over a network
Description Given a file size in mebibytes (MiB) and a network connection speed in Megabits per second (Mb/s), write a program to calculate the estimated time to transfer the file over that network. Assume that all network capacity is used for file data transfer, there is no overhead, loss, congestion, or contention.
Input Two space-delimited positive integers: File size in MiB Network speed in Mb/s For example: 400 10
Output Print an integer representing the number of seconds required to transfer the file over the network. Round the calculated value up to the smallest integer that is not less than the result. For the example above, the output would be: 336

Error Logger
Difficulty: Easy	Test Cases: 7	Published: 2019-04-02
Summary Write a generic error logging function
Description Write a function that accepts some generic error information and writes out a formatted log entry based on a lookup value. The format of the log entry is: \|\|\| The Severity and Error Code are based on the Exception Type. In order to provide the correct values, your solution should use the Exception Type to lookup the correct Severity and Error Code values as shown below: Exception Type Error Code Severity IOException 100 High MemoryException 110 High ThreadAbortException 200 Medium ResponseTimeoutException 300 Low ParameterException 301 Low
Input A single line of input that will have the Exception Type and Message separated by a Pipe "\|" character. For example: IOException\|The file requested does not exist
Output The complete Log Entry with elements separated by a pipe character. For example: High\|100\|IOException\|The file requested does not exist

Even Numbers
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Determine if a number is even or not
Description Write a program that determines whether a number is even or not.
Input Your program should read lines from standard input. Each line consists of one integer between 0 and 5000.
Output Print 1 if the number is even or 0 if the number is odd.

Fee Saver
Difficulty: Easy	Test Cases: 7	Published: 2019-04-18
Summary Optimize a buffer using some inspection and rules
Description A bank wants to change the way they apply transactions to accounts in order to minimize fees for their customers. Each day, the transactions for a given account come in. They can be applied to the account in any order but when an overdraft occurs, a flat fee is charged for each transaction that results in a balance below zero. Write a program that accepts an account's starting balance plus a list of transactions for the day. Re-order the transactions in any way you like to minimize the number of overdraft fees. Report the number of overdraft fees resulting from your optimization.
Input The first line of input will be a numeric value representing the starting balance of the account. All subsequent lines will be transaction amounts for the day to be applied against the starting balance. Amounts may be negative (debits) or positive (credits).
Output An integer indicating the fewest number of overdraft fees possible considering the daily transactions.

Fibonacci Series
Difficulty: Easy	Test Cases: 5	Published: 2012-10-08
Summary Print out the nth fibonacci number
Description The Fibonacci series is defined as F(0) = 0; F(1) = 1; F(n) = F(n-1) + F(n-2) where n>1. Given a positive integer n, print the value of F(n).
Input Your program should read lines of text from standard input. Each line will contain a single positive integer, n.
Output For each input n, print to standard output the fibonacci number, F(n), one per line.

Find a Writer
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Find a famous writer in a string
Description You have a set of rows with names of famous writers encoded inside. Each row is divided into 2 parts by a pipe char (\|). The first part has a writer's name. The second part is a "key" to generate a name. Your goal is to go through each number in the key (numbers are separated by space) left-to-right. Each number represents a position in the 1st part of a row. This way you collect a writer's name which you have to output.
Input Your program should read lines from standard input. Each line contains a string of characters, followed by a pipe char (\|), followed by a string of space-delimited numbers.
Output Print the decoded name/birth year of the writer.

Fizz Buzz
Difficulty: Easy	Test Cases: 5	Published: 2012-08-17
Summary A simple game involving divisibility tests.
Description Given positive integers A, B, and N, write a program that prints integers from 1 to N. But for integers that are multiples of A, print 'F', and for multiples of B, print 'B'. For integers which are multiples of both A and B, print 'FB'.
Input Your program should read lines of text from standard input. Each line will contain A, B, and N as space-delimited positive integers.
Output For each line of input, print to standard output a line of space-delimited integers 1 through N, replacing integers as described above.

Frowny Smileys
Difficulty: Easy	Test Cases: 12	Published: 2019-11-15
Summary Count the number of frowning smileys in a string
Description Write a program to count the total number of frowny smileys in a string. Here are the rules for how to find smileys and determine whether they are happy or frowny: Optionally, a smiley may start with eyebrows. Eyebrows are marked with the character >. Each smiley must have a pair of eyes. The characters used for eyes are :, ;, or 8. Using only eyes, it's difficult to determine whether a smiley is happy or not. So you need to proceed further with the analysis. Optionally, a smiley may cry. Any tears must follow the eyes and are marked with the character '. But be careful, they could be tears of happiness. Optionally, a smiley may have a nose marked with -, o or ~. The last and most evident sign of the smiley's mood is its mouth. A frowny smiley has a mouth marked with one of these characters: (, C, <, [, {, or @. The distinguishing feature of a happy smiley face is a mouth marked with ), ], }, D, or 3. Each smiley starts with eyebrows or eyes and ends with the mouth. Use regular expression(s) for the search.
Input A string with text containing some number of smileys. For example: I want to buy a onesie… :o) but know >;-( it won’t suit me :'{
Output Print out the number of frowny smileys found in the string. For example: 2

Graph Degree
Difficulty: Easy	Test Cases: 8	Published: 2019-06-24
Summary Find a minimum and a maximum degree of the simple undirected graph
Description Write a program that finds the minimum and the maximum degree of a simple undirected graph. In other words, the minimum and the maximum degrees of the graph's vertices. A degree of the vertex is the number of edges that are incident to it.
Input A simple undirected graph represented as an adjacency matrix that is a square n x n matrix containing only zeros and ones. The element in position i row and j column is equal to 1 if and only if there is an edge between vertices i and j in the graph. Each row of input contains a space-separated series of elements for that corresponding row of the adjacency matrix. For example: 0 1 1 1 1 1 0 0 0 0 1 0 0 1 1 1 0 1 0 0 1 0 1 0 0 The first row means that the first vertex is adjacent to (i.e., shares an edge with) the vertices 2, 3, 4, and 5. So the degree of the first vertex is 4 because 4 edges are incident to it. The second row means that vertex 2 is adjacent only to vertex 1, and its degree is equal to 1.
Output A space-separated minimum and maximum degree of the given graph. For example: 1 4

Greatest Common Divisor
Difficulty: Easy	Test Cases: 5	Published: 2012-10-08
Summary Greatest common divisor of two numbers
Description Write a program that finds the greatest common divisor of two positive integers.
Input Your program should read lines from standard input. Each line contains two positive integers separated by a comma.
Output For each pair of input integers, print to standard output their GCD, one GCD per line.

Hailstone Sequence
Difficulty: Easy	Test Cases: 12	Published: 2020-03-06
Summary Print a hailstone sequence of numbers
Description The Collatz Conjecture defines a sequence of numbers starting from any positive integer n and obtaining each term of the sequence from the previous term in the following way: If the previous number is even, divide it by two If the previous number is odd, triple it and add one This sequence is called a hailstone sequence and can be described mathematically as: The Collatz conjecture states that such a sequence will always reach a final value of 1. Write a program to generate the hailstone sequence starting from n and ending with 1.
Input An integer 1 < n < 10000, that is the first number in the sequence.
Output Print a space-delimited list of integers in the hailstone sequence as described. For example, if the first number n = 5, the output would be: 5 16 8 4 2 1

Happy Numbers
Difficulty: Easy	Test Cases: 7	Published: 2012-10-08
Summary Determine if a number is a happy number or not
Description A happy number is defined by the following process. Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers, while those that do not end in 1 are unhappy numbers.
Input Your program should read lines of text from standard input. Each line contains a single positive integer, N.
Output If the number is a happy number, print 1 to standard output. Otherwise, print 0. For the curious, here's why 7 is a happy number: 7->49->97->130->10->1. Here's why 22 is NOT a happy number: 22->8->64->52->29->85->89->145->42->20->4->16->37->58->89 ...

Hello World
Difficulty: Easy	Test Cases: 5	Published: 2018-09-11
Summary Implement the classic code sample in multiple languages
Description Print the text "HELLO WORLD" to standard output in the language requested. Languages that need to be supported are English, French and Spanish.
Input An ISO standard culture code. For example, "en-US". This should be case insensitive.
Output "HELLO WORLD" stated in the requested language. All output should be in UPPER CASE.

Hex to Decimal
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Convert a hex number to its decimal equivalent.
Description You will be given a hexadecimal (base 16) number. Convert it into decimal (base 10).
Input Your program should read lines from standard input. Each line contains a hex number. You may assume that the hex number does not have the leading '0x'. Also, all alpha characters (a through f) in the input will be in lowercase.
Output Print out the equivalent decimal number.

Hidden Digits
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Try to look behind the scenes
Description In this challenge you're given a random string containing hidden and visible digits. The digits are hidden behind lower case latin letters as follows: 0 is behind 'a', 1 is behind ' b ' etc., 9 is behind 'j'. Any other symbol in the string means nothing and has to be ignored. So the challenge is to find all visible and hidden digits in the string and print them out in order of their appearance.
Input Your program should read lines from standard input. Each line contains a string. You may assume that there will be no whitespace inside the string.
Output For each test case, print out all visible and hidden digits in order of their appearance. Print out NONE if there are no digits in the string.

JSON Menu IDs
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Calculate IDs in JSON menu
Description You have a JSON string which describes a menu. Calculate the SUM of all "id" fields in the menu for items that also have a "label" field.
Input Your program should read lines from standard input. Each line contains a JSON object that represents a menu. Each ID in the menu is between 0 and 100. Each menu has a maximum of 10 items.
Output Print the sum of the id's of menu items that also have a label.

Kennel Counting
Difficulty: Easy	Test Cases: 4	Published: 2019-04-02
Summary Perform basic JSON handling
Description A pet adoption agency needs to keep track of their inventory. Given a set of data describing the monthly intake of pets, count and group the pets by Type and Breed.
Input A list of pets to inventory expressed in JSON format. For example: { "Pets":[ { "Breed":"Dingo", "IsFixed":false, "Name":"Fido", "Source":"Australia Kennel Network", "Type":"Dog" }, { "Breed":"Siamese", "IsFixed":true, "Name":"Fluffy", "Source":"Lost and Found", "Type":"Cat" } ] }
Output A list that includes each Type, Breed, and Count in a line-by-line report that is sorted alphabetically. For example: Cat Siamese 1 Dog Dingo 1

Kitchen View
Difficulty: Easy	Test Cases: 4	Published: 2019-04-02
Summary Pivot a set of data into a summary of counts
Description A restaurant ordering system accepts food orders one item at a time. Each item entered is for a specific person sitting at a particular table. The kitchen is not concerned with which person ordered which item. They just need to know what menu items have been ordered for each table. Write a program that will read a list of individual orders and "pivot" that set into a display of food items for each table in the diner. The total number of each item per table will be displayed on a column for that food item. For example, the orders: Sarah,7,Green Salad Sarah,7,Cappuccino Michael,2,Club Sandwich Marcus,5,Sparkling Water Would be displayed for the kitchen as: Table,Cappuccino,Club Sandwich,Green Salad,Sparkling Water 2,0,1,0,0 5,0,0,0,1 7,1,0,1,0 Note that the menu items are listed in alphabetical order across the overall list.
Input A comma-delimited list of names, table numbers, and menu items.
Output A comma-delimited list of table numbers and item counts with a header row as the first line. The first column name is "Table".

Largest Difference
Difficulty: Easy	Test Cases: 7	Published: 2012-10-08
Summary Find the largest difference between integers in a list
Description Write a program that finds the greatest difference between integers in a list. The list can contain positive and negative integers.
Input Your program should read lines from standard input. Each line contains a comma-separated list of integers.
Output For each input list, print to standard output the greatest difference between any two integers in the list. Print each difference on its own line.

Least Common Multiple
Difficulty: Easy	Test Cases: 6	Published: 2012-10-08
Summary Least common multiple of two numbers
Description Write a program that finds the least common multiple of two positive integers.
Input Your program should read lines from standard input. Each line contains two positive integers separated by a comma.
Output For each pair of input integers, print to standard output their LCM, one LCM per line.

Letter Transformation
Difficulty: Easy	Test Cases: 7	Published: 2012-10-08
Summary Transform letters in a string
Description Write a program that transforms strings of lowercase alphabet characters by replacing each letter with the subsequent character in the english alphabet. For example, replace 'a' with 'b', 'p' with 'q', and 'z' with 'a'.
Input Your program should read lines from standard input. Each line will contain lowercase english letters.
Output For each input string, print the transformed string to standard output, one string per line.

Longest Word
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Get the longest word in a sentence
Description In this challenge you need to find the longest word in a sentence. If the sentence has more than one word of the same length you should pick the one that appears first.
Input Your program should read lines from standard input. Each line has one or more words. Each word is separated by a space char.
Output Print the longest word in the sentence.

Lowercase
Difficulty: Easy	Test Cases: 4	Published: 2012-10-08
Summary Lowercase text
Description Given a string, write a program to convert it into lowercase.
Input Your program should read lines of text from standard input. Each line will be a sentence containing characters from the English alphabet.
Output For each input sentence, print to standard output the lowercase version of the sentence, one sentence per line.

Lowest Unique Number
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Find the lowest unique number in a set
Description You are playing a game with several friends. Each of your friends chooses a number between 1 and 9 (inclusive) and writes it down on a piece of paper. You, as the judge, collect all the papers and must determine the winner. The winner of the game is the player who submitted the lowest unique number. There are 10-20 players in the game.
Input Your program should read lines from standard input. You are the judge, and you're given a set of space-delimited numbers from players for each round of game.
Output Print the winner's position in the input list, or 0 if there is no winner (there are no unique numbers). In the first sample test case, the lowest unique number is 6. So player 5 wins.

Major Element
Difficulty: Easy	Test Cases: 8	Published: 2014-02-28
Summary Find the major element in a sequence
Description The major element in a sequence with length L is the element which appears in a sequence more than L/2 times. The challenge is to find that element in a sequence. L is in range [100, 2000].
Input Your program should read lines from standard input. Each line of the file contains a sequence of integers separated by commas. Each integer is in range [0, 100].
Output For each sequence, print out the major element or print "None" if there is no such element.

Manchester Decoding
Difficulty: Easy	Test Cases: 9	Published: 2019-04-18
Summary Decode binary number from a Manchester code
Description In telecommunications, Manchester code is a form of digital encoding in which data bits are represented by transitions from one logical state to another. It is used in Ethernet's physical layer, Radio-frequency identification (RFID) and Near-field communication (NFC). According to the IEEE 802.3 convention, each zero-valued bit is encoded by a transition from one to zero: 10. Conversely, a one-valued bit is expressed by a zero-to-one transition: 01 Write a program to decode positive binary numbers from Manchester encoding.
Input A Manchester-encoded binary form of an integer. For example: 0110010110
Output Write the decoded positive integer in binary form. For example: 10110 If the input value is invalid and cannot be decoded, write "ERROR".

Manchester Encoding
Difficulty: Easy	Test Cases: 8	Published: 2019-04-18
Summary Encode binary number with a Manchester code
Description In telecommunications, Manchester code is a form of digital encoding in which data bits are represented by transitions from one logical state to another. It is used in Ethernet's physical layer, Radio-frequency identification (RFID) and Near-field communication (NFC). According to the IEEE 802.3 convention, each zero-valued bit is encoded by a transition from one to zero: 10 Conversely, a one-valued bit is expressed by a transition from zero to one: 01 Write a program to encode positive binary numbers using Manchester encoding.
Input A positive integer in binary form. For example: 10110
Output Manchester code of the number. For example: 0110010110

Max Range Sum
Difficulty: Easy	Test Cases: 5	Published: 2013-12-20
Summary Given a list of positive and negative integers, find the largest possible sum of any number of consecutive integers.
Description Bob is developing a new strategy to get rich in the stock market. He wishes to invest his portfolio for 1 or more days, then sell it at the right time to maximize his earnings. Bob has painstakingly tracked how much his portfolio would have gained or lost for each of the last N days. Now he has hired you to figure out what would have been the largest total gain his portfolio could have achieved. Example: Bob kept track of the last 10 days in the stock market. On each day, the gains/losses are as follows: 7 -3 -10 4 2 8 -2 4 -5 -2. If Bob entered the stock market on day 4 and exited on day 8, his gains would have been 16 (4 + 2 + 8 + -2 + 4).
Input The input consists of integers on a line separated by spaces. The input contains N, the number of days (0 < N < 10000), followed by N integers D (-10000 < D < 10000) indicating the gain or loss on that day.
Output For each test case, print a line containing the maximum possible gain over the period. If no gain is possible, print 0.

Median Filter
Difficulty: Easy	Test Cases: 7	Published: 2019-07-15
Summary Apply a standard median filter to a series of data
Description Finally, you get the latest measurements in your scientific experiment. It was not easy to collect that data. A lot of noise is present in the space around your secret laboratory. But you know that it's not hard to improve the quality of the measured signal, applying a median filter to the raw data from analog-to-digital converters. Write a program that filters out the noise from the raw data, using the standard median filter. An output of the filter at some point is the median value of N samples around that point. Another way to describe that is a window of size N elements slides over the input signal, element by element. On every step, the median of the elements in the window is written to the output. The median of the set of integers is the middle element in the sorted list of these numbers. For simplicity, assume that the size of the filter window is always odd. Do not process the boundaries of the input signal, where it's not enough elements to compose a window of the necessary size. In other words, just crop the signal. If the filter's window size is 5 you will lose 2 first and 2 last elements. For example, let's filter signal 17 18 19 37 21 22 23 85 25 26 using a window of size 3. For the first 3 elements 17 18 19 the median is 18. Shifting filter's window to the next 3 elements 18 19 37 gives 19 as an output. 19 37 21 outputs 21, and so on. +------+----------+--------+ \| step \| elements \| median \| +------+----------+--------+ \| 1 \| 17 18 19 \| 18 \| +------+----------+--------+ \| 2 \| 18 19 37 \| 19 \| +------+----------+--------+ \| 3 \| 19 37 21 \| 21 \| +------+----------+--------+ \| 4 \| 37 21 22 \| 22 \| +------+----------+--------+ \| 5 \| 21 22 23 \| 22 \| +------+----------+--------+ \| 6 \| 22 23 85 \| 23 \| +------+----------+--------+ \| 7 \| 23 85 25 \| 25 \| +------+----------+--------+ \| 8 \| 85 25 26 \| 26 \| +------+----------+--------+ Processing all integers from the set will result in 18 19 21 22 22 23 25 26. As you can see, there are no spikes and outlying elements in the output data set.
Input The first line contains an odd integer, the size of the filter's window. Each next line of the input has a comma-separated series of positive integers. That is raw data of the measured signal. For example: 3 5,5,5,15,5,5,5 1,2,3,25,5,6,52,7,8
Output Print out a comma-separated series of integers, that is a result of applying the standard median filter to the raw input data. For example: 5,5,5,5,5 2,3,5,6,6,7,8

Merge Step
Difficulty: Easy	Test Cases: 6	Published: 2019-04-18
Summary Merge and sort two sets using a specific algorithm
Description Your colleague has 15 years of log files full of performance data. The data needs to be sorted, but the file sizes are so big that it's impossible to load them all into memory at once. Your colleague decided to use a merge sort to divide the data into smaller chunks, sort them recursively, then merge results to produce the final sorted file with all data. Your task is to write the core Merge Step function for the process. This function needs to combine two sorted subarrays into a single, sorted subarray Your program should: Compare the two unused lowest elements in each of the subarrays as a pair Copy the first of the two values to the resulting array based on standard ASCII/UTF-8 sort order Repeat steps 1 and 2 until one of the arrays is empty Finally, copy remaining data in the non-empty subarray to the resulting array
Input Two comma-separated, sorted arrays of alphanumeric characters (UTF-8). The pair of arrays are separated by a semicolon. For example: 1,4,7,8;2,3,5,6
Output Write the merged and sorted result as comma-separated elements on the first line. Write each pair that was compared during merge process on the second line. Elements in each pair must be sorted and comma separated then enclosed in parenthesis. For example: 1,2,3,4,5,6,7,8 (1,2)(2,4)(3,4)(4,5)(5,7)(6,7)

Minimum Distance
Difficulty: Easy	Test Cases: 10	Published: 2013-12-20
Summary Given a list of points on a number line, find a new point with the smallest sum of distances to every given point.
Description Alice is looking for a sorority to join for her first year at Acme University. There is a street consisting entirely of sorority houses near the university, and some of her high school friends have already joined sorority houses on the street. (More than one of her friends may live at the same sorority house.) Alice wants to visit her friends frequently, and needs a program that will help her pick an optimal house to visit them from. Each sorority house has a street number that indicates its location on the street. The optimal location will minimize the sum of differences between the number of Alice's house and the number of her friends' houses. Example: Alice's friends live at houses 3, 3, 5, and 7. Alice moves in at house 4. Then the distances to her friends' houses are 1, 1, 1, and 3, totaling 6.
Input The input consists of several integers on a line, separated by spaces. The first integer F contains the number of friends (0 < F < 100). Then F street addresses A follow (0 < A < 10000).
Output Print a line containing the minimal sum of distances for an optimal sorority location.

Mixed Content
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Separate words from digits
Description You have a string of words and digits separated by commas. Write a program which separates the words in the string from digits. You shouldn't change the order of the elements.
Input Your program should read lines from standard input. Each line contains a comma-delimited list of numbers and strings.
Output Print out the two new lists separated by a pipe char (\|). If one of the lists is empty, omit the pipe char. Be sure to print elements in the same order they appeared in the original list.

Morse Code
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Decode Morse code
Description You have received a text encoded with Morse code and want to decode it.
Input Your program should read lines from standard input. Each line contains a Morse code message. Each letter in the code is separated by a space char, each word is separated by 2 space chars. The input will contain encoded letters and numbers only.
Output Print out the decoded words.

Multiples of a Number
Difficulty: Easy	Test Cases: 4	Published: 2012-10-08
Summary Multiples of a number greater than another number.
Description Given numbers x and n, where n is a power of 2, print the smallest multiple of n which is greater than or equal to x. Do not use the division or modulo operator.
Input Your program should read lines of text from standard input. Each line will contain the integers x and n, separated by a comma.
Output For each line of input, print to standard output the smallest multiple of n which is greater than or equal to x, one per line.

Multiply Lists
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Multiply elements in 2 lists
Description You have 2 lists of positive integers. Write a program which multiplies corresponding elements in these lists.
Input Your program should read lines from standard input. Each line contains two space-delimited lists. The lists are separated with a pipe char (\|). Both lists have the same length, in range [1, 10]. Each element in the lists is a number in range [0, 99].
Output Print the multiplied list.

N mod M
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Determine the modulus (without the modulus operator).
Description Given two integers N and M, calculate N mod M (without using any built-in modulus operator).
Input Your program should read lines from standard input. Each line contains two comma-delimited integers, N,M. You may assume M will never be zero.
Output Print out the value of N mod M.

Network Bandwidth
Difficulty: Easy	Test Cases: 12	Published: 2020-03-06
Summary Calculate network bandwidth
Description Given a measured file transfer time in seconds and file size in mebibytes (MiB), write a program to calculate the network's bandwidth in Megabits per second (Mb/s). Assume that all network capacity is used for the file data transfer, there is no overhead, loss, congestion, or contention.
Input Two space-delimited positive integers: File size in MiB Transfer time in seconds For example: 400 336
Output Print an integer number that is the network's bandwidth in Mb/s. Round the calculated real value up to the smallest integer that is not less than the result. For the example above, the output would be: 10

Number Trick
Difficulty: Easy	Test Cases: 6	Published: 2012-11-01
Summary Number Trick
Description Write a program that computes an integer's checksum. To compute the checksum, break the integer into its constituent digits and, working from right to left, doubling every second digit. If the product results in a number with two digits, treat those two digits independently. Then, sum all the digits for the final checksum. For example, 1496 has a checksum of 21. We compute this by first breaking 1496 into constituents and doubling the ever second digit => 6, 18, 4, 2. Then, the individual digits are summed as 6 + (1 + 8) + 4 + 2 = 21.
Input Your program should read lines from standard input. Each line contains one integer.
Output For each line of input, print to standard output the integer's checksum, one checksum per line.

One's Complement
Difficulty: Easy	Test Cases: 6	Published: 2012-11-06
Summary Find the one's complement of a binary number
Description Write a program to find the one’s complement of a binary number. The one’s complement of a binary number is obtained by ‘flipping’ every 0 bit to 1 and every 1 bit to 0.
Input Your program should read lines from standard input. Each line contains a positive integer in binary form.
Output For each line of input, print to standard output the one's complement of the binary number, also as a binary number. Print out each result on a new line.

Order Statistic
Difficulty: Easy	Test Cases: 7	Published: 2019-05-31
Summary Find k order statistic of the array
Description Write a program that, given an array of n distinct integers and number k, will determine the k order statistic of the array. kis an integer between 1 and n : 1 ≤ k ≤ n. The k order statistic is the k smallest entry in the array. So the n order statistic is simply the maximum value in the set. The median, in other words, the middle element, is the order statistic.
Input The first line of input will contain the order of statistic k to determine. The second line of input will contain a space-separated array of integers to use for the statistical set. For example: 3 5 2 9 7
Output The integer that is determined to be the k order statistic of the given array. For example: 7

Pairwise Divisible Subset
Difficulty: Easy	Test Cases: 12	Published: 2020-03-06
Summary Find the largest pairwise divisible subset of integers
Description Given a set of distinct integers, find the largest subset such that in every pair of elements, the larger element is evenly divisible by the smaller. So if the pair of elements is (a, b) and a < b then b is divisible by a. If a > b then a is divisible by b. HINT: If every integer in the set A is divisible by x, and x is divisible by y then every integer in the set A is divisible by y.
Input A space-delimited set of integers. For example: 3 5 12 4 7 24 6 10
Output The largest space-delimited subset of pairwise divisible integers in ascending order. For example: 3 6 12 24

Penultimate Word
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Find the next-to-last word
Description Alice has invented a new card game to play with Bob. Alice made a deck of cards with random values between 1 and 52. Bob picks 5 cards. Then, he has to rearrange the cards so that by utilizing the operations plus, minus, or times, the value of the cards reach Alice's favorite number, 42. More precisely, find operations such that ((((val1 op1 val2) op2 val3) op3 val4) op4 val5) = 42. Help Bob by writing a program to determine whether it is possible to reach 42 given 5 card values. For example, Bob picks 5 cards out of the deck containing 40, 1, 3, 4, and 20. Bob rearranges the cards and supplies four operations, so that 4 * 20 - 40 + 3 - 1 = 42.
Input Your program should read lines from standard input. Each line is a string of space-delimited words (with no punctuation). Each line has at least two words.
Output Print the next-to-last word.

Pirate Loot
Difficulty: Easy	Test Cases: 12	Published: 2020-01-11
Summary Obtain a distribution of values using a set of rules
Description In the Caribbean Sea, pirates robbed a merchant ship and plundered a chest full of gold coins. The pirates used simple rules on how to distribute the treasure: The captain divides the coins into separate piles and places all the piles in a line The crew members take regular turns, selecting one pile of gold at a time for themselves Each pirate can choose to take either the leftmost or rightmost pile of gold Assume that all pirates are greedy and always take the biggest pile of gold they can. For example, if the values of three piles are 1 3 2, the pirate will choose the rightmost pile which has the value of 2. If piles of gold are equal on both sides, for consistency, the rightmost pile must be taken. Write a program to calculate the total value of gold that each pirate will obtain, given the number of pirates N in the crew and an array of values for each pile.
Input The first line of input contains a positive integer N, which is the count of pirates in the crew. The second line of input contains a space-delimited array of positive integers, representing the total value of gold coins in each pile. For example: 3 5 3 2 4 3
Output Print a space-delimited array of N integers, where each integer is a total value of gold received by each pirate in the crew, from the first to the last. The table below shows the turns taken by pirates and the amount of gold obtained by each of them. +--------+--------+-------------+-------+ \| \| \| Values left \| Value \| \| Turn \| Pirate \| in a line \| of \| \| Number \| Number \| before \| gold \| \| \| \| the turn \| taken \| +--------+--------+-------------+-------+ \| 1 \| 1 \| 5 3 2 4 3 \| 5 \| +--------+--------+-------------+-------+ \| 2 \| 2 \| 3 2 4 3 \| 3 \| +--------+--------+-------------+-------+ \| 3 \| 3 \| 3 2 4 \| 4 \| +--------+--------+-------------+-------+ \| 4 \| 1 \| 3 2 \| 3 \| +--------+--------+-------------+-------+ \| 5 \| 2 \| 2 \| 2 \| +--------+--------+-------------+-------+ After summing up the values taken by each pirate in our example, the final result will be: 8 5 4

Power of two
Difficulty: Easy	Test Cases: 8	Published: 2012-11-06
Summary Determine if a number is a power of two
Description Write a program, given a positive integer, determines if the number is an exact power of two.
Input Your program should read lines from standard input. Each line contains a positive integer.
Output For each line of input, print to standard output 'true' if the number is an exact power of two and 'false' if not. Print out each result on a new line.

Query Board
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Set and get values from a matrix using tiny DSL.
Description There is a board (matrix). Every cell of the board contains one integer, which is 0 initially. The following operations can be applied to the Query Board: SetRow i x: change all values in the cells on row "i" to value "x". SetCol j x: change all values in the cells on column "j" to value "x". QueryRow i: output the sum of values on row "i". QueryCol j: output the sum of values on column "j". The board's dimensions are 256x256. "i" and "j" are integers from 0 to 255. "x" is an integer from 0 to 31.
Input Your program should read lines from standard input. Each line contains one of the above operations.
Output For each query, output the result of the query.

Queue Implementation
Difficulty: Easy	Test Cases: 12	Published: 2020-01-11
Summary Implement a queue data structure
Description Write a program implementing a queue, a First-In-First-Out (FIFO) data structure. The queue should have enqueue and dequeue methods: The enqueue method must insert a given element to the back of the queue. The dequeue method must remove the element from the front of the queue. The queue must have a certain capacity which is the maximum number of elements in the data structure. The enqueue method must do nothing if the queue is full. And similarly, the dequeue method must do nothing if the queue is empty. You will be asked to perform a sequence of operations with integers and then print out the state of the queue.
Input The first line of input contains a positive integer defining the capacity of the queue. Each additional line of input contains a string naming the operation to be performed: enqueue or dequeue. The enqueue string will be followed by an integer that must be inserted into the queue. For example: 5 enqueue 5 enqueue 6 enqueue 1 dequeue enqueue 2 dequeue enqueue 3
Output Print a space-delimited list of the integers that the queue will contain after all operations have been performed. The order of the elements must be from the front to the back of the queue. For example, using the input shown above, the queue would contain: 1 2 3 Print Empty if the queue will be empty after all operations.

Removing Vowels
Difficulty: Easy	Test Cases: 6	Published: 2012-11-05
Summary Remove all vowels from a sentence
Description Write a program that, given a sentence, strips out all the vowels (‘a’, ‘e’, ‘i’, ‘o’, ‘u’). The string can contain a mix of upper/lowercase and both uppercase and lowercase vowels need to be removed.
Input Your program should read lines from standard input. Each line contains a sentence.
Output For each line of input, print to standard output the sentence obtained by removing all uppercase/lowercase vowels, one per line.

Reverse words
Difficulty: Easy	Test Cases: 5	Published: 2012-10-08
Summary Reversing an input sequence of words.
Description Write a program to reverse the words of a sentence.
Input Your program should read lines of text from standard input. Each line contains a sentence.
Output Print to standard output each sentence with its words reversed, one sentence per line. Empty lines in the input should be ignored. Ensure that your output contains no trailing spaces.

Rightmost Char
Difficulty: Easy	Test Cases: 6	Published: 2012-10-08
Summary Print the position of the rightmost occurrence of a char.
Description Given a string S and a character t, print the position (zero based) of the rightmost occurrence of t (case matters) in S or -1 if t does not exist in S.
Input Your program should read lines of text from standard input. Each line will contain a string S and a character t, separated by a comma. Ignore all empty lines.
Output For each line of input, print to standard output the zero based position of the character t in string S, one position per line.

Road Trip
Difficulty: Easy	Test Cases: 6	Published: 2014-02-28
Summary Do not be left without gasoline
Description You've decided to make a road trip across the country in a straight line. You have chosen the direction you'd like to travel and made a list of cities in that direction that have gas stations to stop at and fill up your tank. To make sure that this route is viable, you need to know the distances between the adjacent cities in order to be able to travel this distance on a single tank of gasoline, (No one likes running out of gas.) but you only know distances to each city from your starting point.
Input Your program should read lines from standard input. Each line contains the list of cities and distances to them, comma delimited, from the starting point of your trip. You start your trip at point 0. The cities with their distances are separated by semicolons.
Output Print out the distance from the starting point to the nearest city, and the distances between two nearest cities separated by comma, in order they appear on the route.

Robotic Vacuum Cleaner
Difficulty: Easy	Test Cases: 12	Published: 2020-02-08
Summary Check if the robotic vacuum cleaner returns to its base station
Description A robotic vacuum cleans a room by starting from a base station and making a series of moves. The sequence is represented by a string containing one of the following characters for each move: U - Up D - Down R - Right L - Left Given a string with the sequence of moves, check whether or not the robotic vacuum returns to its base station. Assume that each individual move covers the same distance in the given direction.
Input A string containing the characters U, D, R, L describing the robot's sequence of moves. For example: ULLRURDD
Output Print True if the robotic vacuum cleaner returns to the base station. Otherwise, print False.

Roman Numerals
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Convert a cardinal number to a Roman numeral
Description Many people are familiar with the Roman numerals for relatively small numbers. The symbols I (capital i), V, X, L, C, D, and M represent the decimal values 1, 5, 10, 50, 100, 500 and 1000 respectively. To represent other values, these symbols, and multiples where necessary, are concatenated, with the smaller-valued symbols written further to the right. For example, the number 3 is represented as III, and the value 73 is represented as LXXIII. The exceptions to this rule occur for numbers having units values of 4 or 9, and for tens values of 40 or 90. For these cases, the Roman numeral representations are IV (4), IX (9), XL (40), and XC (90). So the Roman numeral representations for 24, 39, 44, 49, and 94 are XXIV, XXXIX, XLIV, XLIX, and XCIV, respectively. More details can be found here: Roman numerals Write a program to convert a cardinal number to a Roman numeral.
Input Your program should read lines from standard input. Each line contains a cardinal number N (1 <= N <= 3999).
Output Print out the value of N in Roman numerals.

Rosetta Stone
Difficulty: Easy	Test Cases: 6	Published: 2019-04-02
Summary Decode a message using a keyed structure
Description The Rosetta stone is an ancient decree written into stone that was used by archeologists to translate between Greek and Ancient Egyptian languages. Write a program to decode messages using a Rosetta for translation. The "Rosetta" will be a series of character sets paired with English words or characters. If you translate the encrypted message correctly, you will find the hidden message. HINT: Spaces that are not part of a fragment must be preserved
Input Multiple lines of input will be given. The first line of input will be the message to translate to English. All other lines of input will be the Rosetta needed to translate. The fragments of each pair will be separated by a pipe character, one pair per line of input. For example: Hola Mundo Mundo\|World Lunes\|Monday Hola\|Hello Translates: Hola Mundo into: Hello World
Output The translated text, which will be a real English phrase

Rotated List Search
Difficulty: Easy	Test Cases: 6	Published: 2019-04-02
Summary Correct and search a list that has been rotated
Description Write a program to search a list of integers for a set of values. The list of integers is sorted in ascending order, but also rotated a random number of positions, making it unclear where the list begins. For example, consider this list of integers to search: 62 78 99 1 5 7 11 13 17 27 It is sorted from 1 to 99 but "rotated" three positions such that the starting point of the list is no longer correct. Given this rotated list, find a way to search for a supplied list of values that may or may not be present in the list.
Input Two lines of input as follows: A space delimited string of integer values to locate in the list. A space delimited string of integer values that has been sorted, but rotated a random number of positions. For example, 1 11 17 62 78 99 1 5 7 11 13 17 27
Output For each value to locate, print out the zero-based index of the item in the un-rotated input list. If a value does not exist, print out -1 for that item. Given the example input, the correct output would be: 0 3 5

Run Kitty, Run
Difficulty: Easy	Test Cases: 10	Published: 2019-11-15
Summary Calculate if it possible for the cat to escape from dogs
Description A cat is in a large field with a single big tree growing on it. Unfortunately, the cat has been surrounded by wild dogs which are trying to catch it. All dogs can run faster than the cat, so there is no chance for the cat to run away from the field. The only hope for the cat is to escape up the tree. The cat runs to the tree in a straight line at a fixed speed. The dogs understand the cat's escape plan and run to the tree, also in a direct line, with a higher speed trying to intercept the cat. Given the initial positions and velocities of the animals and the position of the tree, calculate if the cat will escape. To escape successfully, the cat has to reach the tree before than any of the dogs.
Input The first line of input contains three real numbers separated by a space: x coordinate of the cat's initial position y coordinate of the cat's initial position The cat's velocity The second line contains two real numbers: x coordinate of the tree y coordinate of the tree The third line has a positive integer, N, the number of dogs where 1 ≤ N ≤ 100. Each additional N lines contain three real numbers each: x and y coordinates of the initial position and the velocity of each dog. For example: 0.0 0.0 1.0 3.0 4.0 2 12.0 12.0 2.0 -10.0 -10.0 3.0 All coordinates are in meters and velocities are in meters per second. All real numbers have exactly one digit after the decimal point.
Output A single line with Escaped or Captured, depending on whether the cat can beat all the dogs to the tree or not.

Self Describing Numbers
Difficulty: Easy	Test Cases: 7	Published: 2012-10-08
Summary Determine if a number is a self-describing number or not
Description A number is a self-describing number when (assuming digit positions are labeled 0 to N-1), the digit in each position is equal to the number of times that that digit appears in the number.
Input Your program should read lines of text from standard input. Each line contains a single positive integer, N.
Output For each input N, print 1 to standard output if N is a self-describing number. Otherwise, print 0. For the curious, here's how 2020 is a self-describing number: Position 0 has value 2 and there are two 0s in the number. Position 1 has value 0 because there are no 1's in the number. Position 2 has value 2 and there are two 2's. And the position 3 has value 0 and there are zero 3's.

Set Differences
Difficulty: Easy	Test Cases: 8	Published: 2019-04-02
Summary Compare two sets to identify unique values
Description Write a program that accepts two sets of alphanumeric characters and compares them. Your code should identify the elements that are in the first set but not the second set and output the results.
Input Two lines of input, where each line is a space-delimited series of uppercase alphanumeric values that represents the set. For example: Z 3 X 2 Y 1 A Z B Y 2 1
Output The set of values that are unique in the first set sorted alphanumerically, by digits and then characters. For example: 3 X If no unique values exist, output NULL

Set Intersection
Difficulty: Easy	Test Cases: 4	Published: 2012-10-08
Summary Print the intersection of two sets of numbers.
Description Find the intersection of two sorted lists of integers.
Input Your program should read lines of text from standard input. Each line will contain two comma separated lists of integers in ascending order, one pair of lists per line. The lists are separated by a semicolon.
Output For each pair of input lists, print to standard output their sorted intersection in ascending order, comma separated, one intersection per line.

Shortest Repetition
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Find the shortest repetition in a string
Description Write a program to determine the shortest repetition in a string. A string is said to have period p if it can be formed by concatenating one or more repetitions of another string of length p. For example, the string "xyzxyzxyzxyz" has period 3, since it is formed by 4 repetitions of the string "xyz". It also has periods 6 (two repetitions of "xyzxyz") and 12 (one repetition of "xyzxyzxyzxyz").
Input Your program should read lines from standard input. Each line contains a string of up to 80 non-blank characters.
Output Print out the smallest period of the input string.

Simple Sorting
Difficulty: Easy	Test Cases: 10	Published: 2014-02-20
Summary Sort several numbers
Description Write a program which sorts numbers.
Input Your program should read lines from standard input. Each line contains space-separated decimal numbers.
Output Print the numbers exactly as they appear in the input, in sorted order.

Snail - a Wall Climber
Difficulty: Easy	Test Cases: 12	Published: 2019-12-03
Summary Write a program to calculate how many days are required for a snail to climb up a wall
Description A snail climbs on a wall, it starts at the bottom and climbs up n meters a day. Regretfully, every night it slides m meters down. Given the height of the wall H, write a program to calculate how many days required for the snail to reach the top of the wall.
Input Three non-negative integers n , m , and H separated by a space. For example: 3 2 11
Output A single integer number, which is the number of days required for the snail to reach the top of the wall. For example: 9 If the snail will never be able to reach the top of the wall print Fail

Split the Number
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Evaluate the number according to the pattern
Description You are given a number N and a pattern. The pattern consists of lowercase latin letters and one operation "+" or "-". The challenge is to split the number and evaluate it according to this pattern e.g. 1232 ab+cd -> a:1, b:2, c:3, d:2 -> 12+32 -> 44
Input Your program should read lines from standard input. Each line contains the number and the pattern separated by a single whitespace. The number will be in range [100, 1000000000]. All test cases contain valid expressions (no leading zeros).
Output Print out the result of the pattern evaluation.

Stock Trader - Simple Bearish Cross
Difficulty: Easy	Test Cases: 5	Published: 2019-04-18
Summary Check a series of stock prices for a trading signal without calculating stats
Description A classic stock trading pattern happens when a 9-Day Moving Average (9-DMA) crosses the 50-Day Moving Average (50-DMA). This can be indicative of a bullish or a bearish setup, depending on the direction. When the 9-DMA crosses below the 50-DMA from above, it is bearish. When the 9-DMA cross above the 50-DMA from below, it is bullish. Write a program that reads in a series of dates and stats, inspects the 9-DMA and 50-DMA, then returns the dates of any bearish signals that occurred.
Input A series of price statistics in the following format: Date\|Price\|9DMA\|50DMA Dates will follow ISO 8601 format YYYY-MM-DD. Prices will be in a non-localized format with two-decimal places with no currency indications. For example: 2016-01-01\|22.05\|22.19\|21.93 2016-01-02\|22.45\|22.01\|21.99 2016-01-03\|23.57\|21.78\|22.07
Output A date in ISO 8601 format where a bearish signal occurred. If no bearish signal happened, return the string NULL For example: 2016-01-02

Stock Trader - Simple Bullish Cross
Difficulty: Easy	Test Cases: 5	Published: 2019-04-19
Summary Check a series of stock prices for a trading signal without calculating stats
Description A classic stock trading pattern happens when a 9-Day Moving Average (9-DMA) crosses the 50-Day Moving Average (50-DMA). This can be indicative of a bullish or a bearish setup, depending on the direction. When the 9-DMA crosses below the 50-DMA from above, it is bearish. When the 9-DMA cross above the 50-DMA from below, it is bullish. Write a program that reads in a series of dates and stats, inspects the 9-DMA and 50-DMA, then returns the dates of any bullish signals that occurred.
Input A series of price statistics in the following format: Date\|Price\|9DMA\|50DMA Dates will follow ISO 8601 format YYYY-MM-DD. Prices will be in a non-localized format with two-decimal places with no currency indications. For example: 2016-01-01\|22.05\|21.78\|21.93 2016-01-02\|22.45\|22.01\|21.99 2016-01-03\|23.57\|22.19\|22.07
Output A date in ISO 8601 format where a bullish signal occurred. If no bullish signal happened, return the string NULL For example: 2016-01-02

Sum Numbers
Difficulty: Easy	Test Cases: 8	Published: 2012-11-05
Summary Sum two numbers to arrive at the third
Description Write a program that, given a list of three numbers, determines if it is possible to add two of the numbers to arrive at the third.
Input Your program should read lines from standard input. Each line contains a comma separated list of three integers.
Output For each line from standard input, print 'true' or 'false' to standard output if any of the two input numbers can be added to arrive at the third, one per line.

Sum of Digits
Difficulty: Easy	Test Cases: 5	Published: 2012-10-08
Summary Sum of digits comprising a number
Description Given a positive integer, find the sum of its constituent digits.
Input Your program should read lines of text from standard input. Each line will contain a single positive integer.
Output For each input integer, print to standard output the sum of the digits that comprise it, one sum per line.

Sum of Integers from File
Difficulty: Easy	Test Cases: 2	Published: 2012-10-08
Summary Print the sum of integers read from a file.
Description Print out the sum of integers read from a file.
Input Your program should read lines of text from standard input. Each line will contain a single positive integer.
Output Print to standard output the sum of all the integers.

Swap Case
Difficulty: Easy	Test Cases: 6	Published: 2012-11-05
Summary Swapping the case of letters in a sentence
Description Write a program that, given a sentence, swaps the case of each character in the sentence. Assume all characters are from the ASCII character set. Punctuation symbols should be left as is.
Input Your program should read lines from standard input. Each line contains a sentence.
Output For each line of input, print to standard output the sentence obtained by swapping the case of each character, one per line.

Swap Elements
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Swap elements in a list
Description You are given a list of numbers which is supplemented with positions that have to be swapped.
Input Your program should read lines from standard input. Each line contains a list of space-delimited numbers, followed by a colon, followed by the indexes to be swapped. The first position in the list is at index 0. If there is more than one pair of indexes to be swapped, process each pair in the order they appear in the input, left to right.
Output Print the new list.

Swap Numbers
Difficulty: Easy	Test Cases: 6	Published: 2012-11-05
Summary Swapping numbers surrounding a word
Description Write a program that, given a sentence where each word has a single digit positive integer as a prefix and suffix, swaps the numbers while retaining the word in between. Words in the sentence are delimited from each other by a space.
Input Your program should read lines from standard input. Each line contains a sentence. Each word in the sentence begins and ends with a single digit positive integer i.e. 0 through 9. Assume all characters are ASCII.
Output For each line of input, print to standard output the sentence obtained by swapping the numbers surrounding each word, one per line.

Time Difference
Difficulty: Easy	Test Cases: 6	Published: 2012-11-07
Summary Calculate the time difference between two clock times
Description Write a program that, given two clock times, prints out the absolute number of minutes between them.
Input Your program should read lines from standard input. Each line contains two wall clock times separated by a hyphen. Wall clock time is defined as hh:mm followed by AM' or 'PM', e.g. '09:05 AM'
Output Print to standard output the number of minutes between the two times from standard input. Print out each result on a new line.

URL Parsing
Difficulty: Easy	Test Cases: 6	Published: 2012-11-02
Summary Parsing out components of a URL
Description Write a program that, given a URL, parses out and displays its constituent components. For the purpose of this challenge, a URL is of the form <protocol>://<domain>/path?<query string>. Print out the protocol, domain, and query string, separated by commas.
Input Your program should read lines from standard input. Each line contains a URL. There is one URL per line.
Output For each line of input, extract and print a line to standard output. The output should be a comma-separated list of the protocol, domain, and query string of the URL (in that order). In case any of the components are missing, leave them blank in the output.

Unique Elements
Difficulty: Easy	Test Cases: 4	Published: 2012-10-08
Summary Extract unique list from a sorted list of numbers.
Description Write a program to remove duplicates from lists.
Input Your program should read lines of text from standard input. Each line will contain a comma separated list of sorted integers.
Output For each input list, print the list to standard output with duplicates removed, one list per line.

Word Flip
Difficulty: Easy	Test Cases: 5	Published: 2019-04-02
Summary Manipulate strings and words
Description Write a program to break down a complex string into words and transpose them. The manipulation must reverse each individual word so it's backwards and also write them out to individual lines in the order of the original sentence. For example: Hello World Would be "flipped" to: olleH dlroW
Input Any single-line string that may or may not resemble a sentence. Spaces will separate each "word".
Output Individual words from the input string printed one word per line. The letters of each word must be in reversed order. Whitespace should be excluded from output.

Word Search
Difficulty: Easy	Test Cases: 12	Published: 2019-11-15
Summary Find all words satisfying given criteria
Description Write a program to find all words in a string that satisfy the following conditions: Contains characters a - z, A - Z, digits 0 - 9, or underscore Starts with a capital letter A - Z Has at least one digit 0 - 9 Any character that does not fit the first condition can be used to separate distinct words. Use regular expression(s) to search.
Input A string in which to search. For example: Theory Lab_99 society Imagi4nation
Output Print out the list of found words in order of their appearance in the input string. Print each word on a separate line. For example: Lab_99 Imagi4nation Print NONE if there are no words in the string, matching necessary rules.

Word to Digit
Difficulty: Easy	Test Cases: 10	Published: 2014-02-28
Summary Substitute words to digits
Description Given a string representation of a set of numbers, print the digit representation of the numbers.
Input Your program should read lines from standard input. Each line contains a list of word representations of numbers separated by a semicolon. There are up to 20 numbers in one line. The numbers are "zero" through "nine".
Output Print the sequence of digits.

Add Number Series

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Add Number Series II

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Adjacency List

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Adjacency Matrix

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Alter Case

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Armstrong Numbers

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Asteroid Mining

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Avocado Prices

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Beautiful Strings

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Binary Addition

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Binary Coded Decimal - Encoding

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Bit Positions

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Cached Out

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Calculate Distance

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Camel Case Machine

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Capitalize Words 2

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