Update bt_construct_inorder_postorder.py

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bt3gl 2023-08-08 19:51:19 -07:00 committed by GitHub
parent b9318bf6ea
commit bbdd47ffd3
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@ -3,7 +3,7 @@
# author: bt3gl
def build_tree(left, right, index_map):
def build_tree(left, right, index_map, postorder):
if left > right:
return None
@ -11,15 +11,15 @@ def build_tree(left, right, index_map):
root = Node(postorder.pop()) # this order change from preorder
index_here = index_map[root.val]
root.right = build_tree(index_here + 1, right, index_map) # this order change from preorder
root.left = build_tree(left, index_here - 1, index_map)
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, postorder)
return root
def build_tree(inorder, postorder) -> Optional[Node]:
def build_tree(inorder, postorder):
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)