题解 | #对称的二叉树#

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 pRoot TreeNode类 
     * @return bool布尔型
     */
    public boolean isSymmetrical (TreeNode pRoot) {
        // write code here
        return resuYesno(pRoot, pRoot);
    }
    boolean resuYesno(TreeNode pRoot1,TreeNode pRoot2){
        if(pRoot1 == null && pRoot2 == null){
            return true;
        }
        if(pRoot1 == null || pRoot2 == null || pRoot1.val != pRoot2.val)    {   
            return false;
        }
        return resuYesno(pRoot1.left,pRoot2.right) && resuYesno(pRoot1.right,pRoot2.left);
    }
}