题解 | #牛群的轴对称结构#
牛群的轴对称结构
https://www.nowcoder.com/practice/a200535760fb4da3a4568c03c1563689
import java.util.*;
/*
* public class TreeNode {
* int val = 0;
* TreeNode left = null;
* TreeNode right = null;
* public TreeNode(int val) {
* this.val = val;
* }
* }
*/
public class Solution {
/**
* 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
*
*
* @param root TreeNode类
* @return bool布尔型
*/
public boolean isSymmetric (TreeNode root) {
// write code here
if(root == null) return true;
return isSymmetric(root.left,root.right);
}
boolean isSymmetric(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 isSymmetric(left.left,right.right) && isSymmetric(left.right,right.left);
}
}
使用构造函数，对树的左子树的左子树与树的右子树进行对比，对左子树的右子树与树的右子树的左子树进行对比，结果都相同才返回true
