LeetCode Online Judge 题目C# 练习 - Balanced Binary Tree

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 everynode never differ by more than 1.

 1         public static bool BalancedBinaryTree(BTNode root)

 2         {

 3             if (root == null)

 4                 return true;

 5 

 6             if(Math.Abs(GetDepth(root.Left) - GetDepth(root.Right)) >= 2)

 7                 return false;

 8             else

 9                 return BalancedBinaryTree(root.Left) && BalancedBinaryTree(root.Right);

10         }

11 

12         public static int GetDepth(BTNode root)

13         {

14             if (root == null)

15                 return 0;

16             if (root.Left == null && root.Right == null)

17                 return 1;

18             else

19                 return 1 + Math.Max(GetDepth(root.Left), GetDepth(root.Right));

20        

代码分析：

　　看来是永无止境了，LeetCode上加了些Tree的题目，在做些吧，反正自己递归很弱。

　　上面是递归Top-down的做法，不知有没有bottom-up的做法，DP之类的。