I’ve been doing the Weekly Challenges (http://theweeklychallenge.org/). The latest (https://theweeklychallenge.org/blog/perl-weekly-challenge-381/) involved finding properties of arrays. (Note that this ends today.) Task 1: Same Row Column You are given a n x n matrix containing integers from 1 to n. Write a script to find if every row and every column contains all the integers from 1 to n. This is a traversal in two stages, and it's easier if one can return from the function early (PostScript can't, Typst doesn't like to, and Scala is so purist that it can't even break out of a loop). But in PostScript: By default return true if no reason is found to change that. Row by row first: Build a set of all required numbers. Remove each number in the row from that set. If there's anything left, the return will be false. If the return is still true, check the columns. Iterate over column numbers. Again, build the set of required numbers. But iterate over the array, picking out the correct column entry from each row. Task 2: Smaller Greater Element You are given an array of integers. Write a script to find the number of elements that have both a strictly smaller and greater element in the given array. This is very similar to challenge 231 task 1 "Min Max" — except that here we want the length of the list of matching elements, not the list itself. So I recycled my existing code, except for Crystal, Scala and Typst, which I wasn't writing at the time. In Raku: Full code on codeberg (https://codeberg.org/Firedrake/theweeklychallenge/src/branch/main/381/).