Tree (16) -- Validate Binary Search Tree

Validate Binary Search Tree

Given a binary tree, determine if it is a valid binary search tree (BST).

bool isValid(TreeNode* root, long long maxLimit, long long minLimit){ if(root==NULL) return true; if(!(root->val < maxLimit && root->val > minLimit)){ return false; } return isValid(root->left, root->val, minLimit)&& isValid(root->right, maxLimit, root->val); } bool isValidBST(TreeNode* root) { if(root==NULL) return true; return isValid(root->left, root->val, LONG_MIN) && isValid(root->right, LONG_MAX, root->val); }