LeetCode 110 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 every node never differ by more than 1.

本来想在一个方法里搞定，可是脑袋打不过来弯弯儿，必须调用求树的高度的方法。

如果有一个方法搞定的答案，欢迎留言。

public boolean isBalanced(TreeNode root) {
return depth(root) >= 0;
}

public int depth(TreeNode root) {
if (root == null) return 0;
int highL = depth(root.left);
int highR = depth(root.right);
if (Math.abs(highL - highR) > 1 || highL < 0 || highR < 0) return -1;
return Math.max(highL, highR) + 1;
}