[Leetcode]110. Balanced Binary Tree

Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.

/** * Definition for a binary tree node. * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    bool isBalanced(TreeNode* root) {        return balancedHeight(root) >= 0;    }        int balancedHeight(TreeNode* root) {        if (root == nullptr)            return 0;        int left = balancedHeight(root->left);        int right = balancedHeight(root->right);        if (left < 0 || right < 0 || abs(left - right) > 1)            return -1;        return max(left, right) + 1;                }};