226. 翻转二叉树

问题
例子

思路


答案

/**
 * 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 L = root.left;
        root.left = invertTree(root.right);
        root.right = invertTree(L);
        return root;
    }
}

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def invertTree(self, root: TreeNode) -> TreeNode:
        if root==None: return None
        root.left,root.right = self.invertTree(root.right),self.invertTree(root.left)
        return root