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
        if (pRoot==null)
            return true;
        return judgeTwoTree(pRoot.left, pRoot.right);
    }
    public boolean judgeTwoTree(TreeNode p1,TreeNode p2){
        if (p1==null)
            return p2==null;
        if (p2==null)
            return p1==null;
        if (p1.val!=p2.val)
            return false;
        return judgeTwoTree(p1.left,p2.right)&&judgeTwoTree(p1.right,p2.left);
    }
}