剑指offer66题--Java实现，c++实现和python实现 18.二叉树的镜像

题目描述

操作给定的二叉树，将其变换为源二叉树的镜像。

输入描述:

二叉树的镜像定义：源二叉树 
    	    8
    	   /  \
    	  6   10
    	 / \  / \
    	5  7 9 11
    	镜像二叉树
    	    8
    	   /  \
    	  10   6
    	 / \  / \
    	11 9 7  5

C++

/*
struct TreeNode {
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
			val(x), left(NULL), right(NULL) {
	}
};*/
class Solution {
public:
    void Mirror(TreeNode *pRoot) {
        if (pRoot == nullptr)
            return;
        TreeNode *tp = pRoot->left;
        pRoot->left = pRoot->right;
        pRoot->right = tp;
        Mirror(pRoot->left);
        Mirror(pRoot->right);
    }
};

Java

/**
public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;

    }

}
*/
public class Solution {
    public void Mirror(TreeNode root) {
        TreeNode next=null;
        if(root==null)
            return;
        next=root.left;
        root.left=root.right;
        root.right=next;
        if(root.left!=null){
            Mirror(root.left);
        }
        if(root.right!=null){
            Mirror(root.right);
        }
    }
}

python

# -*- coding:utf-8 -*-
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None
class Solution:
# 返回镜像树的根节点
    def Mirror(self, root):
        # write code here
        if root is None:
            return 
        temp = root.left
        root.left = root.right
        root.right = temp
        self.Mirror(root.left)
        self.Mirror(root.right)
        return root