LeetCode之旅（22）

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 ofevery node never differ by more than 1.

/** * Definition for binary tree * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    bool isBalanced(TreeNode *root) {        if (!root) return true;        if (abs(treeDepth(root->left)-treeDepth(root->right))>1)            return false;        return isBalanced(root->left) && isBalanced(root->right);    }    int treeDepth(TreeNode *p) {        if (!p) return 0;        return 1+max(treeDepth(p->left), treeDepth(p->right));    }};