JZ39 平衡二叉树

https://www.nowcoder.com/practice/8b3b95850edb4115918ecebdf1b4d222

import java.lang.Math;

public class Solution {
    public boolean IsBalanced_Solution(TreeNode root) {
        return getDepth(root) != -1;
    }
    
    private int getDepth(TreeNode root) {
        if (root == null) return 0;

        int left = getDepth(root.left);
        if (left == -1) return -1;

        int right = getDepth(root.right);
        if (right == -1) return -1;

        // 检查高度差是否大于 1
        return Math.abs(left - right) > 1 ? -1 : 1 + Math.max(left, right);
    }
}