def test_strings(self):
tree = PrefixTree()
input_strings = [] # Strings that have been inserted into the tree
for string in ['ABC', 'ABD', 'A', 'XYZ']: # Strings to be inserted
# Insert new string and add to list of strings already inserted
tree.insert(string)
input_strings.append(string)
# Verify tree can retrieve all strings that have been inserted
tree_strings = tree.strings()
assert len(tree_strings) == len(input_strings) # Check length only
self.assertCountEqual(tree_strings, input_strings) # Ignore order
def test_init_and_properties(self):
tree = PrefixTree()
# Verify tree size property
assert isinstance(tree.size, int)
assert tree.size == 0
# Verify root node
assert isinstance(tree.root, PrefixTreeNode)
assert tree.root.character == PrefixTree.START_CHARACTER
assert tree.root.is_terminal() is False
assert tree.root.num_children() == 0
def test_insert_with_string(self):
tree = PrefixTree()
tree.insert('AB')
# Verify root node
assert tree.root.character == PrefixTree.START_CHARACTER
assert tree.root.is_terminal() is False
assert tree.root.num_children() == 1
assert tree.root.has_child('A') is True
# Verify node 'A'
node_A = tree.root.get_child('A')
assert node_A.character == 'A'
assert node_A.is_terminal() is False
assert node_A.num_children() == 1
assert node_A.has_child('B') is True
# Verify node 'B'
node_B = node_A.get_child('B')
assert node_B.character == 'B'
assert node_B.is_terminal() is True
assert node_B.num_children() == 0
def test_insert_with_4_strings(self):
tree = PrefixTree()
# Insert new string that starts from root node
tree.insert('ABC')
# Verify root node
assert tree.root.character == PrefixTree.START_CHARACTER
assert tree.root.is_terminal() is False
assert tree.root.num_children() == 1
assert tree.root.has_child('A') is True
# Verify new node 'A'
node_A = tree.root.get_child('A')
assert node_A.character == 'A'
assert node_A.is_terminal() is False
assert node_A.num_children() == 1
assert node_A.has_child('B') is True
# Verify new node 'B'
node_B = node_A.get_child('B')
assert node_B.character == 'B'
assert node_B.is_terminal() is False
assert node_B.num_children() == 1
assert node_B.has_child('C') is True
# Verify new node 'C'
node_C = node_B.get_child('C')
assert node_C.character == 'C'
assert node_C.is_terminal() is True
assert node_C.num_children() == 0
# Insert string with partial overlap so node 'B' has new child node 'D'
tree.insert('ABD')
# Verify root node again
assert tree.root.character == PrefixTree.START_CHARACTER
assert tree.root.is_terminal() is False
assert tree.root.num_children() == 1
assert tree.root.has_child('A') is True
# Verify node 'A' again
assert node_A.character == 'A'
assert node_A.is_terminal() is False
assert node_A.num_children() == 1
assert node_A.has_child('B') is True
# Verify node 'B' again
assert node_B.character == 'B'
assert node_B.is_terminal() is False
assert node_B.num_children() == 2 # Node 'B' now has two children
assert node_B.has_child('C') is True # Node 'C' is still its child
assert node_B.has_child('D') is True # Node 'D' is its new child
# Verify new node 'D'
node_D = node_B.get_child('D')
assert node_D.character == 'D'
assert node_D.is_terminal() is True
assert node_D.num_children() == 0
# Insert substring already in tree so node 'A' becomes terminal
tree.insert('A')
# Verify root node again
assert tree.root.character == PrefixTree.START_CHARACTER
assert tree.root.is_terminal() is False
assert tree.root.num_children() == 1
assert tree.root.has_child('A') is True
# Verify node 'A' again
assert node_A.character == 'A'
assert node_A.is_terminal() is True # Node 'A' is now terminal
assert node_A.num_children() == 1 # Node 'A' still has one child
assert node_A.has_child('B') is True # Node 'B' is still its child
# Insert new string with no overlap that starts from root node
tree.insert('XYZ')
# Verify root node again
assert tree.root.character == PrefixTree.START_CHARACTER
assert tree.root.is_terminal() is False
assert tree.root.num_children() == 2 # Root node now has two children
assert tree.root.has_child('A') is True # Node 'A' is still its child
assert tree.root.has_child('X') is True # Node 'X' is its new child
# Verify new node 'X'
node_X = tree.root.get_child('X')
assert node_X.character == 'X'
assert node_X.is_terminal() is False
assert node_X.num_children() == 1
assert node_X.has_child('Y') is True
# Verify new node 'Y'
node_Y = node_X.get_child('Y')
assert node_Y.character == 'Y'
assert node_Y.is_terminal() is False
assert node_Y.num_children() == 1
assert node_Y.has_child('Z') is True
# Verify new node 'Z'
node_Z = node_Y.get_child('Z')
assert node_Z.character == 'Z'
assert node_Z.is_terminal() is True
assert node_Z.num_children() == 0
def test_complete(self):
strings = ['ABC', 'ABD', 'A', 'XYZ']
tree = PrefixTree(strings)
# Verify completions for all substrings
assert tree.complete('ABC') == ['ABC']
assert tree.complete('ABD') == ['ABD']
assert tree.complete('AB') == ['ABC', 'ABD']
assert tree.complete('BC') == []
assert tree.complete('BD') == []
assert tree.complete('A') == ['A', 'ABC', 'ABD']
assert tree.complete('B') == []
assert tree.complete('C') == []
assert tree.complete('D') == []
assert tree.complete('XYZ') == ['XYZ']
assert tree.complete('XY') == ['XYZ']
assert tree.complete('YZ') == []
assert tree.complete('X') == ['XYZ']
assert tree.complete('Y') == []
assert tree.complete('Z') == []
def test_contains(self):
strings = ['ABC', 'ABD', 'A', 'XYZ']
tree = PrefixTree(strings)
# Verify contains for all substrings
assert tree.contains('ABC') is True
assert tree.contains('ABD') is True
assert tree.contains('AB') is False
assert tree.contains('BC') is False
assert tree.contains('BD') is False
assert tree.contains('A') is True
assert tree.contains('B') is False
assert tree.contains('C') is False
assert tree.contains('D') is False
assert tree.contains('XYZ') is True
assert tree.contains('XY') is False
assert tree.contains('YZ') is False
assert tree.contains('X') is False
assert tree.contains('Y') is False
assert tree.contains('Z') is False
def test_size_with_repeated_insert(self):
tree = PrefixTree()
# Verify size after initializing tree
assert tree.size == 0
assert tree.is_empty() is True
# Verify size after first insert
tree.insert('A')
assert tree.size == 1
assert tree.is_empty() is False
# Verify size after repeating first insert
tree.insert('A')
assert tree.size == 1
# Verify size after second insert
tree.insert('ABC')
assert tree.size == 2
# Verify size after repeating second insert
tree.insert('ABC')
assert tree.size == 2
# Verify size after third insert
tree.insert('ABD')
assert tree.size == 3
# Verify size after repeating third insert
tree.insert('ABD')
assert tree.size == 3
# Verify size after fourth insert
tree.insert('XYZ')
assert tree.size == 4
# Verify size after repeating fourth insert
tree.insert('XYZ')
assert tree.size == 4
def test_size_and_is_empty(self):
tree = PrefixTree()
# Verify size after initializing tree
assert tree.size == 0
assert tree.is_empty() is True
# Verify size after first insert
tree.insert('A')
assert tree.size == 1
assert tree.is_empty() is False
# Verify size after second insert
tree.insert('ABC')
assert tree.size == 2
assert tree.is_empty() is False
# Verify size after third insert
tree.insert('ABD')
assert tree.size == 3
assert tree.is_empty() is False
# Verify size after fourth insert
tree.insert('XYZ')
assert tree.size == 4
assert tree.is_empty() is False