LeetCode110 Balanced Binary Tree

Posted 2020-08-18 wangxiaobao的博客

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.（Easy）

分析：

利用辅助函数求深度，然后根据heighted-balanced定义判定即可

代码：

 1 class Solution {
 2     int depth(TreeNode* root) {
 3         if (root == nullptr) {
 4             return 0;
 5         }
 6         return max(depth(root -> left), depth(root -> right)) + 1;
 7     }
 8 public:
 9     bool isBalanced(TreeNode* root) {
10         if (root == nullptr) {
11             return true;
12         }
13         int left = depth(root -> left);
14         int right = depth(root -> right);
15         if (abs(left - right) <= 1 && isBalanced(root -> left) && isBalanced(root -> right)) {
16             return true;
17         }
18         return false;
19     }
20 };