Linked Questions

70
votes
50answers
7k views

Score rock-paper-scissors

Given two string inputs of "Rock", "Paper", or "Scissors", determine the outcome of the RPS round. Output 1 if the first player wins, -1 if the second player wins, or 0 for a tie. ...
50
votes
65answers
18k views

Helloellolloloo Worldorldrldldd

Make a program that takes the word you input, and adds that word to the back of itself minus its first letter, then repeats until all letters are gone. For example, ...
44
votes
67answers
13k views

Hack into a Lottery

You've recently made an account on a dodgy gambling site, where for a fee of 25 dollars, they will pay you back a random amount between 0 and 50 dollars. After getting around 5 dollars twice, you ...
42
votes
85answers
5k views

StringgnirtSStringgnirtSStringgnirtS

Here is a relatively simple challenge for you. Given a string of length N, output the string forwards, then backwards, then forwards, then backwards... etc. N times. For example, if your input was <...
46
votes
69answers
7k views

Make an Emergency Corridor

In some nations there are recommendations or laws on how to form emergency corridors on streets that have multiple lanes per direction. (In the following we only consider the lanes going in the ...
37
votes
88answers
5k views

Print all alphanumeric characters plus underscore

Write a program or function that prints or returns a string of the alphanumeric characters plus underscore, in any order. To be precise, the following characters need to be output, and no more: ...
34
votes
88answers
14k views

Is this number evil?

Introduction In number theory, a number is considered evil if there are an even number of 1's in its binary representation. In today's challenge, you will be identifying whether or not a given number ...
66
votes
50answers
10k views

My daughter's alphabet

The other day we were writing sentences with my daughter with a fridge magnet letter. While we were able to make some(I love cat), we didn't have enough letters to ...
74
votes
41answers
10k views

Fibonacci + Fizz Buzz = Fibo Nacci!

Fibonacci + FizzBuzz = Fibo Nacci! Your challenge is to create a Fibo Nacci program! A Fibo Nacci program outputs the first 100 Fibonacci numbers (starting from 1). If the Fibonacci number is ...
43
votes
66answers
5k views

Blinking twelve

Many electronic devices, specially old ones, will show a blinking 12:00 when the time has not been set. The purpose of this challenge is to recreate this. ...
33
votes
76answers
7k views

Notcalc (Calculate the wrong answer)

Goal: Given two natural numbers (integers from 0 to infinity), output a number that is not the sum of those numbers, but is a natural number. Example solutions (TI-Basic): ...
55
votes
52answers
10k views

How much code would a codegolf golf if a codegolf could golf code?

Write a function or program that takes two words as input and outputs variants of the popular English tongue-twister "How much wood would a woodchuck chuck if a woodchuck could chuck wood?". The ...
32
votes
74answers
4k views

Sum the numbers on standard in

Consider a stream/file with one integer per line. For example: 123 5 99 Your code should output the sum of these numbers, that is ...
54
votes
49answers
7k views

Convert YYYYMM to MMMYY

Basing on this SO question. Challenge is rather simple: given a date period in the format YYYYMM output it in the format MMMYY. ...
51
votes
43answers
5k views

Coprimes up to N

Given a number n >= 2, output all the positive integers less than n where gcd(n, k) == 1 (...

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