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 every node never differ by more than 1.

问题描述：

求解平衡二叉树。

代码实现：

/**
* 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) {
if(root==NULL)
{
return true;
}
int lh=height(root->left);
int rh=height(root->right);
int dif=lh>rh ? lh-rh : rh-lh;
if(dif>1) return false;
else
{
return isBalanced(root->left) && isBalanced(root->right);
}

}
int height(TreeNode* root)
{
if(root==0) return 0;
int lh=height(root->left);
int rh=height(root->right);
return lh>rh ? lh+1 : rh+1;
}
};