【Balanced Binary Tree】cpp

標籤：

題目：

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.

代碼：

/** * 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) return true;            if ( abs(Solution::height(root->left)-Solution::height(root->right)) <= 1 )            {                return Solution::isBalanced(root->left) && Solution::isBalanced(root->right);            }            else            {                return false;            }        }        static int height(TreeNode* p)        {            if (!p) return 0;            return max(Solution::height(p->left),Solution::height(p->right))+1;         }};

tips：

第一次刷這leetcode把此題漏掉了。

注意balanced tree是指every node：

（1）判斷每個節點left和right深度是否相等

（2）再判斷left和right分別是不是balanced的

【Balanced Binary Tree】cpp