题解 | #对称的二叉树#
对称的二叉树
https://www.nowcoder.com/practice/ff05d44dfdb04e1d83bdbdab320efbcb
/* public class TreeNode { int val = 0; TreeNode left = null; TreeNode right = null; public TreeNode(int val) { this.val = val; } } */ import java.util.*; public class Solution { boolean isSymmetrical(TreeNode root) { return recursion(root,root); } //进行判断 boolean recursion(TreeNode root1,TreeNode root2){ //如果根节点都为空说明对称 if(root1==null&&root2==null){ return true; } //有一个节点为空或者两个节点值不同则不对称 if(root1==null||root2==null||root1.val!=root2.val){ return false; } //只有左右子树都对称才返回true return recursion(root1.left,root2.right)&&recursion(root1.right,root2.left); } }