226. 翻转二叉树:
题目链接 :226. 翻转二叉树
题目:
翻转一棵二叉树。
思路:
1、递归:每层左右节点值交换
AC代码:
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode() {}
* TreeNode(int val) { this.val = val; }
* TreeNode(int val, TreeNode left, TreeNode right) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
class Solution {
public TreeNode invertTree(TreeNode root) {
if(root==null)
{
return root;
}
TreeNode tmp=new TreeNode(-1);
tmp=root.left;
root.left=root.right;
root.right=tmp;
invertTree(root.left);
invertTree(root.right);
return root;
}
}