K-th shortest path

Given a weighted directed graph on n nodes (edges [u, v, w] with w >= 1), a source src, a destination dst, and an integer k, return the length of the k-th shortest path from src to dst by total weight. Paths may revisit nodes (so multiple distinct-length routes through cycles count), and the k smallest path lengths are taken in non-decreasing order (with multiplicity). Return -1 if fewer than k distinct paths exist / dst is unreachable in k arrivals.