39、剑指offer--平衡二叉树

题目描述

输入一棵二叉树，判断该二叉树是否是平衡二叉树。

 

解题思路：平衡二叉树，对于每个根节点左右子树高度差小于等于1

class Solution {
public:
    int TreeDepth(TreeNode* pRoot)
    {
        if(pRoot == NULL)
            return 0;
        int nLeft = TreeDepth(pRoot->left);
        int nRight = TreeDepth(pRoot->right);
 
        return (nLeft > nRight)?(nLeft+1):(nRight+1);
    }
    bool IsBalanced_Solution(TreeNode* pRoot) {
        if(pRoot == NULL)
        {
            return true;
        }
        int nLeft = TreeDepth(pRoot->left);
        int nRight = TreeDepth(pRoot->right);
        int diff = nLeft-nRight;
        if(diff < -1 || diff > 1)
            return false;
        return IsBalanced_Solution(pRoot->left) && IsBalanced_Solution(pRoot->right);
    }
};