From fcd4eb423b4d5dbd064ea8454feded875855cbc8 Mon Sep 17 00:00:00 2001 From: bt3gl <138340846+bt3gl-cryptographer@users.noreply.github.com> Date: Tue, 8 Aug 2023 19:56:03 -0700 Subject: [PATCH] Update bt_construct_inorder_preorder.py --- trees/bt_construct_inorder_preorder.py | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/trees/bt_construct_inorder_preorder.py b/trees/bt_construct_inorder_preorder.py index a6faa89..9087fe5 100644 --- a/trees/bt_construct_inorder_preorder.py +++ b/trees/bt_construct_inorder_preorder.py @@ -3,15 +3,16 @@ # author: bt3gl -def build_tree(preorder, inorder) -> Optional[Node]: +def build_tree(preorder, inorder): def helper(left, right, index_map): if left > right: return None - - root = Node(preorder.pop(0)) # # this order change from postorder - index_here = index_map[root.val] + + node = preorder.pop(0) # this order change from postorder + root = Node(node.val) + index_here = index_map[node.val] root.left = helper(left, index_here - 1, index_map) # this order change from postorder root.right = helper(index_here + 1, right, index_map)