/**
* 翻轉一棵二叉樹。
*
* 示例:
*
* 輸入:
*
* 4
* / \
* 2 7
* / \ / \
* 1 3 6 9
*
* 輸出:
*
* 4
* / \
* 7 2
* / \ / \
* 9 6 3 1
*
* 來源:力扣(LeetCode)
* 鏈接:https://leetcode-cn.com/problems/invert-binary-tree
* 著作權歸領釦網絡所有。商業轉載請聯繫官方授權,非商業轉載請註明出處。
*/
/**
* Definition for a binary tree node.
* public class TreeNode {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
class Solution {
public TreeNode invertTree(TreeNode root) {
if (root == null) {
return null;
}
TreeNode right = invertTree(root.right);
TreeNode left = invertTree(root.left);
root.left = right;
root.right = left;
return root;
}
}
解題思路
遞歸