두 갈래 정렬 트리 leetcode_98_Validate Binary Search Tree Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node... 두 갈래 나무두 갈래 정렬 트리중서 역행
leetcode_98_Validate Binary Search Tree Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only nodes with keys less than the node's key. The right subtree of a node... 두 갈래 나무두 갈래 정렬 트리중서 역행