leetcode

commit b9512011fe817ddb7061d8446411bdeecbdbd0b4
parent d5d4fad717c416c1586c24d3b277d72518ca8924
Author: AndrewLockVI <andrewlaack1@gmail.com>
Date:   Wed, 10 May 2023 21:07:04 -0500

Completed postorder traversal problem using dart

Diffstat:
A
binary-tree-postorder-traversal/postorder-traversal.dart
 | 
23
+++++++++++++++++++++++

1 file changed, 23 insertions(+), 0 deletions(-)
diff --git a/binary-tree-postorder-traversal/postorder-traversal.dart b/binary-tree-postorder-traversal/postorder-traversal.dart
@@ -0,0 +1,23 @@
+//Return a list of values in post order.
+//Post order is from bottom to top and left to right.
+//As such it would go bottom left, bottom right, root if there were three values.
+//The time complexity of this code is O(n) where n is the number of nodes in the tree.
+//Time: 255ms Beats: 63.16%
+//Memory: 142.3MB Beats: 5.26%
+
+class Solution {
+  List<int> vals = [];
+  List<int> postorderTraversal(TreeNode? root) {
+      recurse(root);
+      return vals;
+  }
+
+  void recurse(TreeNode? root){
+      if(root == null){
+          return;
+      }
+      recurse(root?.left);
+      recurse(root?.right);
+      vals.add(root.val);
+  }
+}