101.对称二叉树

题目：对称二叉树 点击跳转

文章目录

• 题目描述
• 题目解答

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题目描述

题目解答

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public boolean check(TreeNode left,TreeNode right) {
        if(left == null && right == null){
            return true;
        }
        if(left == null || right == null){
            return false;
        }
        if(left.val != right.val){
            return false;
        }
        return check(left.left,right.right) && check(left.right,right.left);
    }    
    public boolean isSymmetric(TreeNode root) {
        return check(root.left,root.right);
    }
}