[LeetCode]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 everynode never differ by more than 1.

递归，求左右是否平衡，再判断高度差

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