NYRCS Set 13 (Tree orders & diameter) (0/400)

Hint for platonic18 (platonic removal): A tree center is defined as the one or two nodes in the middle of the diameter path. No matter how many possible diameters a tree has, it can be proven that all of them will have the same center(s). Hints for more_lca: 1. Alternate LCA definition - LCA(v1, v2, v3, ...) = deepest node R such that the subtree of R contains all v1, v2, v3... 2. You can use tree orders to tell if some node b is in the subtree of some node a, ie. if b is some child of a. In O(1).