balcanced-binary-tree

题目描述

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:
    int dept(TreeNode *root) {
        if(root==NULL)	return 0;
        if(root->left==NULL && root->right==NULL)
            return 1;
        return max(dept(root->left),dept(root->right))+1;
    }

    bool isBalanced(TreeNode *root) {
        if(root==NULL)	return true;
        int x=dept(root->left)-dept(root->right);
        if(abs(x)>1)
            return false;
        else
            return isBalanced(root->left) && isBalanced(root->right);
    }
};