# All Questions

10,506 questions
8k views

### Am I not good enough for you?

Background: The current Perfect Numbers challenge is rather flawed and complicated, since it asks you to output in a complex format involving the factors of the number. This is a purely decision-...
3k views

### They call me Inspector Morse

Your mission, should you choose to accept it, is to decide whether a given input string is Dot-heavy, or Dash-heavy. A string is dot-heavy when its morse representation contains more dots than dashes....
7k views
+100

Challenge: Input: A list of distinct positive integers within the range $[1, \text{list-size}]$. Output: An integer: the amount of times the list is riffle-shuffled. For a list, this means the ...
569 views

### New Order #1: How does this feel?

Introduction Putting all positive numbers in its regular order (1, 2, 3, ...) is a bit boring, isn't it? So here is a series of challenges around permutations (reshuffelings) of all positive numbers. ...
848 views

### Source permutation

A permutation of a set $S = \{s_1, s_2, \dotsc, s_n\}$ is a bijective function $\pi: S \to S$. For example, if $S = \{1,2,3,4\}$ then the function $\pi: x \mapsto 1 + (x + 1 \mod 4)$ is a ...
224 views

### Shift the weekday!

Employers love to see their employees working hard, while the employees would love to work less, especially those with a monthly rather than hourly payment. The laziest of employees are thinking ...
541 views

### Black Hole challenge from codewars

I came across this challenge from codewars. I wish to know how to solve this problem. The problem description is given below. Its elements are in range[1..n^2]. The matrix is filled by rings, from ...
745 views

### Cycles on the torus

Challenge This challenge will have you write a program that takes in two integers n and m and outputs the number non-...
344 views

### It's Halloween again!

Problem Description We all love a Twix (because it is the best candy), but this is the kids' first Halloween --- we gotta grab at least one of each type of candy for them. Each Halloween all the ...
6k views

### Is it a Cyclops number? “Nobody” knows!

Task: Given an integer input, figure out whether or not it is a Cyclops Number. What is a Cyclops number, you may ask? Well, it's a number whose binary representation only has one ...
5k views

### The (Easy) Road to Code

Input: An integer $n$, which is guaranteed to be $\ge3$. An integer $d$, which is one of $[-1,0,1]$. Output: A road of size $n$, which will be in a north-west direction if $d=-1$; a ...
731 views

### Sum integers in a string

Input A string. Output The sum of all integers in the line. Constraints 1≤Length of line≤500 Sample test Case Input the 5is 108 seCONd4 a Output ...
3k views

### Deal the cards to the players

Tonight is card game night! You are the dealer and your task is to write a program to deal the cards to the players. Given an array of cards and the number of players, you need to split the array of ...
286 views

### Is it a valid penalty shoot-out prefix?

In association football (also known as soccer), a penalty shoot-out is the second tie-breaker measure that may be used in a match which can't end in a tie, after extra time (i.e. association football ...
3k views

### Create chunks from an array

Your task is to write a program which given an array and a number, you need to split the array into chunks with size is number. Rules Your program will receive an array ...
1k views

### Is it possible to make a clamp function shorter than a ternary in JS?

Imagine this short function to clamp a number between 0 and 255: c = n => n > 0 ? n < 255 ? n : 255 : 0 Is this the shortest possible version of a clamp ...
496 views

### Find how “smooth” a number is based on binary

I haven't been on PP&CG for a while, so I thought I would post something! Your task is to find how "smooth" a natural number is. Your method is to: 1: Convert the number to binary 2: Find the ...
3k views

### Make me a metasequence

Background For this challenge, a 'metasequence' will be defined as a sequence of numbers where not only the numbers themselves will increase, but also the increment, and the increment will increase ...
277 views

### Buy the most appropriate items

A store is having a big sale. If your price reaches $199 or more, you can reduce it by$100. You can buy each product only once. Here's an example list of products: (in order to simplify, the names of ...
324 views

### Check if all vowels exist in pairs of strings [closed]

Your program should find the number of string pairs (pairs of 2) that contain all vowels (a e i o u), when given an integer N and ...
2k views

### Compare four integers, return word based on maximum

This function should take four integer inputs (a,b,c,d) ...
201 views

### (bit)Wise Images [closed]

Given a truth table and two images, use the truth table as a bitwise operation to the two images. For example with the truth table: 1 0 1 0 0 0 1 0 (Note that ...
615 views

### Compound Interest… with Wizard Money

Gringotts isn't just a vault, but a reputable financial institution and wizards need loans too. Since you don't want to be screwed over by the Gringotts goblins, you decided it would be a good idea to ...
602 views

### Arrays Start at $\pi$

Your task is to take an array of numbers and a real number and return the value at that point in the array. Arrays start at $\pi$ and are counted in $\pi$ intervals. Thing is, we're actually going ...
261 views

### 45 degree quine [closed]

A very simple golf this time, but should be fun to do. Challenge Output your code, but rotated 45 (or -45) degrees. E.g: lorem ipsum dolor sit amet becomes <...
242 views

### Average Idle-Dice Rolling

So I ran into this progressive/idle game cleverly called Idle Dice. Has a variety of random effects applied to a pretty typical progression formula game. Warning, time sink! Play at your own risk. ...
305 views

### Unique Brick Tilings Within A Rectangle

I was browsing Stackoverflow and saw this question about tiling an MxN rectangle, and I thought it would be great for golfing. Here is the task. Given the dimension M and N, write a program that ...
928 views

### Jumping Numbers

A jumping number is defined as a positive number n which all pairs of consecutive decimal digits differ by 1. Also, all single digit numbers are considered jumping numbers. eg. 3, 45676, 212 are ...
228 views

### Implement MENACE

Background MENACE (Machine Educable Noughts And Crosses Engine) is a rudimentary shallow machine learning algorithm for the game Noughts and Crosses, created by British computer scientist Donald ...
8k views

### Historical difference between / and ÷ in mathematical expressions

Introduction: Inspired by a discussion that is already going on for many years regarding the expression $6÷2(1+2)$. With the expression $6÷2(1+2)$, mathematicians will quickly see that ...
285 views

### Swapless distances

Suppose you have a string $s_0$ and someone else has a hidden string $s_1$. You don't know what $s_1$ is but they tell you that they can get from your string, $s_0$, to their string by making ...
21k views

### It took me a lot of time to make this, pls like. (YouTube Comments #1)

Hold up..... this isn't trolling. Background These days on YouTube, comment sections are littered with such patterns: ...
12k views

### Am I a Rude Number?

For a while now, I've been running into a problem when counting on my fingers, specifically, that I can only count to ten. My solution to that problem has been to count in binary on my fingers, ...
404 views

### Generate a Baseball Pitch String

Goal Write a program or function that takes a positive integer n and randomly generate a legal series of pitches (a Pitch string) of length ...
3k views

### Play Zip, Zap, Zop

There's a little improv warm up game where you arrange yourselves in a circle and send zips, zaps, and zops around by pointing to a person and saying the next word in the sequence, then they do the ...
523 views

### Check type of an integer

You will receive an integer less than 2000000000 and bigger than -2000000000 and you have to test what type(s) of number this is out of: ...
271 views

### Floating over the integers

As you may know, the typical binary floating point numbers in a computer language are quite different than the typical integer numbers in a computer language. Floating point numbers can represent a ...
2k views

### Square Root Distance from Integers

Given a decimal number k, find the smallest integer n such that the square root of n is ...
435 views

### A nasty little memory leak

Below Python code generates memory leak. Challenge: Fix the memory leak with minimal changes to the code as measured by Levenshtein distance to the original code. You may only change the code before ...
15k views

### Eww, those bytes are gross

Write a program or function that, when given a string, filters out as many distinct bytes as it can and returns the cleaned string. However, since your program hates them, none of these bytes can be ...
2k views

### Count repetitions of an array

You will receive an array and must return the number of integers that occur more than once. [234, 2, 12, 234, 5, 10, 1000, 2, 99, 234] This will return 2, since ...
540 views

### Error-detecting Self-repairing Program

Your task is to create a program where if any one character is deleted, it will detect which character was deleted and then re-insert the deleted character in its own source file. For instance, if ...
551 views

### Fizzbuzz in any base

Challenge Input: An integer $b$ between 2 and 62 (inclusive). Output: Count from $1$ to the equivalent of $5000_{10}$ in base $b$, using any reasonable representation for the digits. ...
7k views

### Crack the bank account's password!

Introduction In order to prevent keyloggers from stealing a user's password, a certain bank account system has implemented the following security measure: only certain digits are prompted to be ...
225 views

Challenge Return the full contents of your program, but inverted. How do your invert something? Well, Letters: Take the position of the letter in the alphabet, subtract from 26, and use the letter ...
314 views

### Can this container hold this much liquid?

Can this container hold this much liquid? Challenge Synopsis As you most likely know, liquids have an indefinite shape and a definite volume. As such, they always take the shape of their container. ...
2k views

### Exploding Numbers

sandbox (deleted) Lets define a matrix of 9s as: $$N = \begin{bmatrix} 9&9&9\\9&9&9\\9&9&9 \end{bmatrix}$$ Lets define an exploding number as a number at position $(x,y)$...
2k views

### Build ASCII Podiums

In sporting competitions, it often happens that winners are presented on podiums, with the first-place person on the highest in the middle, the second-place person on the middle height to the left, ...