二叉树的镜像

剑指offer-每日一练

二叉树的镜像

看到这个算法，首先想到的是递归；

package practise;

import structure.TreeNode;

/**
 * @author ：lonus_lan
 * @date ：Created in 2020/1/13 19:33
 * @description： this is the mirror of the binary tree
 * @modified By：
 */
public class TheMirrorOfBinaryTree {
    public static void mirrorRecursive(TreeNode<Integer> root){
        //鲁棒性
        if(root == null || (root.left == null && root.right == null)){
            return;
        }
        TreeNode<Integer> nodeTemp = root.left;
        root.left = root.right;
        root.right = nodeTemp;
        mirrorRecursive(root.left);
        mirrorRecursive(root.right);
    }

    public static void main(String[] args){
        TreeNode<Integer> root = new TreeNode<>(6);
        root.left =new TreeNode<>(8);
        root.right = new TreeNode<>(10);
        root.left.left = new TreeNode<>(4);
        root.left.right = new TreeNode<>(1);
        root.right.left = new TreeNode<>(2);
        root.right.right = new TreeNode<>(3);
        System.out.println(root);
        mirrorRecursive(root);
        System.out.println(root);
    }
}

以后尝试下非递归；

未完待续。