Balanced Binary Tree

 

 

/** * Definition for binary tree * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {    int DFS(TreeNode* root,bool &ret){        if(!ret) return 0;        if(root==NULL)return 0;        int left=0,right=0;        left =DFS(root->left,ret)+1;        right=DFS(root->right,ret)+1;        if(abs(left-right)>1)ret=false;                return max(left,right);            }public:    bool isBalanced(TreeNode *root) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        bool ret=true;        DFS(root,ret);        return ret;            }};