Git-Mirrors/master-algorithms-py
1
0
Fork 0
mirror of https://github.com/autistic-symposium/master-algorithms-py.git synced 2025-04-29 20:26:07 -04:00
Code Issues Packages Projects Releases Wiki Activity

Update bt_construct_inorder_postorder.py

Browse Source
This commit is contained in:
bt3gl 2023-08-08 19:51:19 -07:00 committed by GitHub
parent b9318bf6ea
commit bbdd47ffd3
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 5 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
trees/bt_construct_inorder_postorder.py
View File

@ -3,7 +3,7 @@
# author: bt3gl # author: bt3gl
def build_tree(left, right, index_map): def build_tree(left, right, index_map, postorder):
if left > right: if left > right:
return None return None
@ -11,15 +11,15 @@ def build_tree(left, right, index_map):
root = Node(postorder.pop()) # this order change from preorder root = Node(postorder.pop()) # this order change from preorder
index_here = index_map[root.val] index_here = index_map[root.val]
root.right = build_tree(index_here + 1, right, index_map) # this order change from preorder root.right = build_tree(index_here + 1, right, index_map, postorder) # this order change from preorder
root.left = build_tree(left, index_here - 1, index_map) root.left = build_tree(left, index_here - 1, index_map, postorder)
return root return root
def build_tree(inorder, postorder) -> Optional[Node]: def build_tree(inorder, postorder):
index_map = {val: i for i, value in enumerate(inorder)} index_map = {val: i for i, value in enumerate(inorder)}
return fill_tree(0, len(inorder) - 1, index_map) return fill_tree(0, len(inorder) - 1, index_map, postorder)