/** * 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) {        int flag = 1;        depth(root,0,flag);        if(flag) return true;        else return false;    }        int depth(TreeNode* root,int cnt,int& flag){        if(root == NULL) return cnt;        int a = depth(root->left,cnt+1,flag);        int b = depth(root->right,cnt+1,flag);        if(abs(a-b) > 1) flag = 0;        return max(a,b);    }};

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