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 TreeNode类
 */
 //递归方法解决
public TreeNode Mirror (TreeNode pRoot) {
    // write code here
    if(pRoot == null){
        return null;
    }
    
    TreeNode tmpNode = pRoot.left;
    pRoot.left = pRoot.right;
    pRoot.right = tmpNode;
    
    Mirror(pRoot.left);
    Mirror(pRoot.right);
    
    return pRoot;
}

}