Given n and k, return the k-th permutation of [1, 2, ..., n] in lexicographic order.
Example: n=3, k=3. Permutations in order: [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1]. The 3rd is [2,1,3].
Generating all permutations and picking the k-th works but is slow for large n. Can you compute the k-th directly?
Try it yourself first.