Leetcode 110 Balanced Binary Tree 二叉树

/**
* 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:
int depth(TreeNode* root){
if(!root) return 0;
else{
return max(depth(root->left), depth(root->right)) + 1;
}
}
bool isBalanced(TreeNode* root) {
if(!root) return true;
else if(abs(depth(root->left) - depth(root->right))>1 ){
return false;
}
else return isBalanced(root->left) && isBalanced(root->right);
}
};