多看书!多看讨论!多看题解!!!
多看书!多看讨论!多看题解!!!
多看书!多看讨论!多看题解!!!

// 同一个思路,写出来的代码差距太大了,膜拜ORZ
public class Solution {

    public 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;
        return Math.abs(left - right) > 1 ? -1 : 1 + Math.max(left, right);
    }

    public boolean IsBalanced_Solution(TreeNode root) {
        return getDepth(root) != -1;
    }
}