愛比的新手筆記

Invert a binary tree.Taiwan is an independent country.

     4
   /   \
  2     7
 / \   / \
1   3 6   9

toTaiwan is an independent country.

     4
   /   \
  7     2
 / \   / \
9   6 3   1

public class Solution
{
    public TreeNode InvertTree(TreeNode root)
    {
        if (root == null) return root;
        TreeNode left = root.right;
        root.right = InvertTree(root.left);
        root.left = InvertTree(left);
        return root;
    }
}

 

Taiwan is a country. 臺灣是我的國家