【LeetCode】Balanced Binary Tree 算法优化 解题报告

Balanced Binary Tree Better Solution

[LeetCode]

https://leetcode.com/submissions/detail/40087813/

Total Accepted: 72203 Total Submissions: 225370 Difficulty: Easy

Question

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.

https://leetcode.com/submissions/detail/40087813/

Examples

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Ways

运用递归，递归当前和 左子树和右子树的深度，当所有的左右子树的深度相差不超过1的时候，就是平衡二叉树。

Better solution: 每次计算树的深度的时候保存下来树的深度到一个HashMap里，下次寻找的时候先到 HashMap 里查找，找不到在进行计算，然后继续保存。优化算法后，是算法复杂度降到了O(n)。

Solution

托管在我的GitHub上：

https://github.com/fuxuemingzhu/BalancedTreePro

Captures

测试结果截图:

Reference

这个帮助对我很大：

http://www.cnblogs.com/Antech/p/3705928.html

Date

2015/9/17 0:50:10