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 binary tree * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {private:    int  getDepth(TreeNode *root){        if(root == NULL)            return 0;        int leftDepth = getDepth(root->left);        int rightDepth = getDepth(root->right);        if(leftDepth >= 0 && rightDepth >=0 && abs(leftDepth-rightDepth) <=1 )            return max(leftDepth, rightDepth) +1;        return -1;    }public:    bool isBalanced(TreeNode *root) {        // IMPORTANT: Please reset any member data you declared, as        // the same Solution instance will be reused for each test case.        return getDepth(root) >= 0;    }};