invert binary tree solution

Author: yhkee0404

invert-binary-tree/yhkee0404.rs

@@ -0,0 +1,31 @@
+// Definition for a binary tree node.
+// #[derive(Debug, PartialEq, Eq)]
+// pub struct TreeNode {
+//   pub val: i32,
+//   pub left: Option<Rc<RefCell<TreeNode>>>,
+//   pub right: Option<Rc<RefCell<TreeNode>>>,
+// }
+// 
+// impl TreeNode {
+//   #[inline]
+//   pub fn new(val: i32) -> Self {
+//     TreeNode {
+//       val,
+//       left: None,
+//       right: None
+//     }
+//   }
+// }
+use std::rc::Rc;
+use std::cell::RefCell;
+impl Solution {
+    pub fn invert_tree(root: Option<Rc<RefCell<TreeNode>>>) -> Option<Rc<RefCell<TreeNode>>> {
+        if let Some(u) = &root {
+            let mut u = u.borrow_mut();
+            let v = u.left.clone();
+            u.left = Self::invert_tree(u.right.clone());
+            u.right = Self::invert_tree(v);
+        }
+        root
+    }
+}