题解 | #二叉树的镜像#

简单递归题

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 {
    /**
     * @param pRoot TreeNode类 
     * @return TreeNode类
     */
    public TreeNode Mirror (TreeNode pRoot) {
        if (pRoot == null) {
            return pRoot;
        }
        TreeNode left = pRoot.left;
        TreeNode right = pRoot.right;
        pRoot.left = Mirror(right);
        pRoot.right = Mirror(left);
        return pRoot;
    }
}