[LeetCode] Balanced Binary Tree

[LeetCode] 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 ofeverynode never differ by more than 1.

这道题个人觉得不难，搞清楚平衡BTS的定义就好啦。

还有就是boolean method最后不要想当然的想着反正写了>1就是false就想当然的return true，还是需要用method检查的哦。

public class Solution { public boolean isBalanced(TreeNode root) { if(root == null){ return true; } // situation that unbalanced if(Math.abs(getHeight(root.left)-getHeight(root.right)) > 1){ return false; } // recur test balance return isBalanced(root.left) && isBalanced(root.right); } // getHeight method private int getHeight(TreeNode root){ if(root == null){ return 0; } //aviod 0 we can promise root wont be null but root.left and root.right could be null here return 1+Math.max(getHeight(root.left), getHeight(root.right)); } }