LeetCode 110
Balanced Binary Tree
Problem Description:
判断二叉树是不是平衡二叉树。所谓平衡二叉树,即每个节点的两个子树深度差的绝对值不超过1。
具体的题目信息:
https://leetcode.com/problems/balanced-binary-tree/description/- Example:
- Solution:
/**
* 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 left = TreeDepth(root->left);
int right = TreeDepth(root->right);
int diff = left-right;
if (diff<-1||diff>1)
return false;
return isBalanced(root->left)&&isBalanced(root->right);
}
int TreeDepth(TreeNode* root) {
if (root == NULL) return 0;
int left = TreeDepth(root->left);
int right = TreeDepth(root->right);
return (left>right)?(left+1):(right+1);
}
};