WXM

889. Construct Binary Tree from Preorder and Postorder Traversal Return any binary tree that matches the given preorder and postorder traversals. Values in the traversals pre and post are distinct p...

894. All Possible Full Binary Trees A full binary tree is a binary tree where each node has exactly 0 or 2 children. Return a list of all possible full binary trees with N nodes. Each element of th...

834. Sum of Distances in Tree An undirected, connected tree with N nodes labelled 0…N-1 and N-1 edges are given. The ith edge connects nodes edges[i][0] and edges[i][1] together. Return a list ans,...

99. Recover Binary Search Tree Two elements of a binary search tree (BST) are swapped by mistake. Recover the tree without changing its structure. Example 1: Input: [1,3,null,null,2] 1 / ...

173. Binary Search Tree Iterator Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST. Calling next() will return the next smallest numb...