Have you heard of tralindromes? code-golf string decision-problem palindrome I haven't. :P So I decided to define one: A tralindrome is a string which contains three sections X, Y, Z such that X and Y, and Y and Z overlap by at most one character, and X is equal to the reverse of Y, and Y is equ...

Let’s take a positive integer such as 123. We define the shifted auto-sum of this integer as follows: 123 has 3 digits. We thus consider 3 copies of 123. We stack each copy on top of each other, shifted by 1 digit each time: 123 123 123 We pad each copy with 0s (excluding the last one) to ...

Suppose you have an array with some known set of values (e.g. a string of \$0\$ and \$1\$) and you want to get all the locations of \$1\$s. Instead of storing a list of all the indices, if the \$1\$s come in "clumps" you can sometimes save space by storing starting and ending indices of "runs" of...

All Crossword Grids code-golf In crossword terminology, the grid is the region into which the crossword answers are inserted, consisting of white and black squares. The crossword answers, called entries, are inserted into contiguous sequences of white squares in a row or column, separated by blac...