Newest Questions

17 votes

6 answers

842 views

A palindromic polynomial is a polynomial whose list of coefficients is a palindrome. For example, the polynomial \$p(x) = x^4 + 2x^3 + 3x^2 + 2x + 1\$ is palindromic because its coefficients are \$[1, ...

2 votes

4 answers

575 views

Objective Your challenge is to write a program that, given a paragraph from a book, will output another program that prints out that paragraph. (See my example program in an answer) Scoring The link ...

19 votes

24 answers

2k views

Given X>0, return the smallest Y>=0 such that X+Y is a palindrome. Code golf. Tests: 5 => 0 14 => 8 200 => 2 819 => 9 1100 => 11 1122 => 99

5 votes

3 answers

406 views

Overview You will be given a list of strings. If any two elements are equal, you can delete both of them. If one element a is a substring of element ...

13 votes

8 answers

1k views

You will be given a decimal number n in the form of a string. You must determine if that number, when stored in standard number type ...

11 votes

11 answers

908 views

This came to me in a dream somehow. I've seen similar questions around, but hope this is novel. The premise is straightforward: Input: one positive integer. Output is a pretty square squared using ...

23 votes

5 answers

2k views

In Chinese, each chemical element is named with one Chinese character. (A brief history of the chemical element naming in Chinese can be looked up in Wikipedia.) Your goal: Print a periodic table of ...

16 votes

16 answers

1k views

In a secret lab corridor, there are emitters and gates: A number represents a laser emitter with a certain frequency, a 0 represents an inactive gate. If two ...

16 votes

7 answers

1k views

I'm surprised we don't have the crossed ladders problem as a task here yet. Two ladders of lengths a and b lie oppositely across an alley, as shown in the figure. The ladders cross at a height of h ...

13 votes

9 answers

2k views

Over on Puzzling a couple years ago, Hermant Agarwal proposed the following question: In a certain country the following coins are in circulation: 1 cent, 2 cents, 5 cents, 10 cents, 20 cents, 50 ...

1 vote

2 answers

170 views

Many polyglots fill in the blanks between languages by either making code that is ignored in one language or loading code dynamically. This time, let's write a polyglot that works without that. This ...

15 votes

14 answers

2k views

Problem 4 of the 2025 International Mathematical Olympiad asked (paraphrased): Let \$f(n)\$ be the sum of the largest three proper divisors of \$n\,ドル that is divisors excluding \$n\$ itself. For ...

17 votes

12 answers

921 views

We've been given a map of the night sky. The map features three single characters, to match the theme, I'll refer to them O, X ...

9 votes

2 answers

409 views

Write a program with the following properties: it must be a quine, i.e. running it outputs precisely the program itself; it must take no input; for at least one integer k, it must be the case that ...

13 votes

16 answers

858 views

In the fewest bytes, in any language, write a function, zigzagdefect(n, d) that takes as input integers n and d < n. The function should return a list of length ...