def subtree(s, tree):
"""
Returns whether the given post order traversal index sequence represents a subtree or not
:type s: list
:type tree: Node
:return: result
:rtype: bool
"""
first_node_index = s[0]
last_node_index = s[-1]
# Neglecting explicitly the '_' characters
if '_' in s:
return False
# Checking whether the first node is a leaf
is_non_leaf = Node.has_children(tree, first_node_index)
if is_non_leaf == -1:
return False
# Checking the left most descendant of the root of the subtree, is equal to the first node
lmd = Node.lmd_subtree(tree, last_node_index)
if not lmd:
return False
else:
return not is_non_leaf and lmd == first_node_index
def subtree(s, tree):
"""
Returns whether the given post order traversal index sequence represents a subtree or not
:type s: list
:type tree: Node
:return: result
:rtype: bool
"""
first_node_index = s[0]
last_node_index = s[-1]
# Neglecting explicitly the '_' characters
if '_' in s:
return False
# Checking whether the first node is a leaf
is_non_leaf = Node.has_children(tree, first_node_index)
if is_non_leaf == -1:
return False
# Checking the left most descendant of the root of the subtree, is equal to the first node
lmd = Node.lmd_subtree(tree, last_node_index)
if not lmd:
return False
else:
return not is_non_leaf and lmd == first_node_index
