def test_rotate_left():
'''Test left rotation on the root of a tree.'''
# A full binary search tree.
tree = build_tree([4, 2, 1, 3, 6, 5, 7])
# tree.display()
# The expected result.
target_tree = build_tree([6, 4, 2, 1, 3, 5, 7])
# target_tree.display()
assert target_tree.root.parent == None, \
'tree.parent should have been None.'
assert tree.root.parent == None, 'tree.parent should have been None.'
assert bst.size(tree.root) == 7, 'tree size should be 7.'
assert bst.is_valid_tree(tree.root), 'Valid tree was marked as invalid.'
bst.rotate_left(tree, tree.root)
assert bst.size(tree.root) == 7, 'tree size should be 7.'
assert bst.is_valid_tree(tree.root), 'Valid tree was marked as invalid.'
assert tree.root.parent == None, 'tree.parent should have been None.'
assert tree == target_tree, '__eq__ did not work properly.'
assert not (tree != target_tree), '__ne__ did not work properly.'
def test_rotate_left(self):
'''Test left rotation on the root of a tree.'''
# A full binary search tree.
tree = build_tree([4, 2, 1, 3, 6, 5, 7])
#tree.display()
# The expected result.
target_tree = build_tree([6, 4, 2, 1, 3, 5, 7])
# target_tree.display()
assert target_tree.root.parent == None, \
'tree.parent should have been None.'
assert tree.root.parent == None, 'tree.parent should have been None.'
assert bst.size(tree.root) == 7, 'tree size should be 7.'
assert bst.is_valid_tree(tree.root), \
'Valid tree was marked as invalid.'
bst.rotate_left(tree, tree.root)
assert bst.size(tree.root) == 7, 'tree size should be 7.'
assert bst.is_valid_tree(tree.root), \
'Valid tree was marked as invalid.'
assert tree.root.parent == None, 'tree.parent should have been None.'
# This calls tree.__eq__(target_tree). Cool, huh? You need to write
# the __eq__ method in class BST to do the tree comparison.
assert tree == target_tree, '__eq__ did not work properly.'
# This calls tree.__ne__(target_tree).
assert not (tree != target_tree), '__ne__ did not work properly.'
def test_is_valid():
'''Test the is_valid_tree method from bst.'''
tree = build_tree([3,0,1,4,6])
assert bst.is_valid_tree(tree.root), 'Valid tree was marked as invalid.'
#Manually set a parent pointer to None when the parent BTNode exists
tree.root.right.parent = None
assert not bst.is_valid_tree(tree.root), 'Invalid tree was marked as valid.'
#Fix the parent pointer
tree.root.right.parent = tree.root
assert bst.is_valid_tree(tree.root), 'Valid tree was marked as invalid.'
#Misdirect a parent pointer to an incorrect BTNode
tree.root.left.parent = tree.root.left.right
assert not bst.is_valid_tree(tree.root), 'Invalid tree was marked as valid.'
#Fix the parent pointer
tree.root.left.parent = tree.root
assert bst.is_valid_tree(tree.root), 'Valid tree was marked as invalid.'
#Misdirect a left pointer to an incorrect BTNode
tree.root.left = tree.root.left.right
assert not bst.is_valid_tree(tree.root), 'Invalid tree was marked as valid.'
def test_rotate_subtree_left(self):
'''Test left rotation on the root of a tree.'''
# A full binary search tree.
tree = build_tree([4, 2, 1, 3, 6, 5, 7])
old_tree = build_tree([4, 2, 1, 3, 6, 5, 7])
#tree.display()
#print ""
# The expected result.
target_tree = build_tree([4, 2, 1, 3, 7, 6, 5])
#target_tree.display()
assert tree.root.parent == None, 'tree.parent should have been None.'
assert bst.size(tree.root) == 7, 'tree size should be 7.'
assert bst.is_valid_tree(tree.root), \
'Valid tree was marked as invalid.'
bst.rotate_left(tree, tree.root.right)
assert bst.size(tree.root) == 7, 'tree size should be 7.'
assert bst.is_valid_tree(tree.root), \
'Valid tree was marked as invalid.'
assert tree.root.right.data == old_tree.root.right.right.data, \
'''incorrect rotate, tree's new right substree should start
with 7'''
assert tree.root.data == old_tree.root.data, \
'''incorrect rotate, tree's root should not have changed'''
assert tree.root.right.left.left.data == \
old_tree.root.right.left.data, \
'''incorrect rotate, subtree's leftmost leaf should not have
changed'''
#RL is right.left, and LR is left.right
# This calls tree.__eq__(target_tree). Cool, huh? You need to write
# the __eq__ method in class BST to do the tree comparison.
assert tree == target_tree, '__eq__ did not work properly.'
# This calls tree.__ne__(target_tree).
assert not (tree != target_tree), '__ne__ did not work properly.'
def test_insert_1():
'''Test inserting one node into a BST; also test size and
is_valid_tree.'''
tree = bst.BST()
tree.insert(5)
assert tree.root.data == 5, 'tree.data not correct for tree of size 1.'
assert tree.root.parent == None, 'tree.parent should have been None.'
assert tree.root.left == None, 'tree.left should have been None.'
assert tree.root.right == None, 'tree.right should have been None.'
assert bst.size(tree.root) == 1, 'tree size should be 1.'
assert bst.is_valid_tree(tree.root), 'Valid tree was marked as invalid.'
def test_insert_2_left():
'''Test inserting two nodes into a BST where the second value is inserted
into the left of the root; also test size and is_valid_tree.'''
tree = build_tree([5, 3])
assert tree.root.data == 5, 'tree.data not correct for tree of size 2.'
assert tree.root.parent == None, 'tree.parent should have been None.'
assert tree.root.right == None, 'tree.right should have been None.'
assert tree.root.left.data == 3, 'tree.left should have been 3.'
assert tree.root.left.parent == tree.root, \
"tree.left's parent should be root."
assert bst.size(tree.root) == 2, 'tree size should be 2.'
assert bst.size(tree.root.left) == 1, "tree.left's size should be 1."
assert bst.is_valid_tree(tree.root), 'Valid tree was marked as invalid.'
def play_game(tree_size):
'''Play the rotation game with tree_size nodes in the tree.'''
# Blank the screen and make the trees.
media.add_rect_filled(pic, 0, 0, 400, 400, media.white)
game_tree = random_tree(tree_size)
target_tree = random_tree(tree_size)
# Draw the new trees; the current node is initially the root.
curr = game_tree.root
draw(pic, game_tree.root, 0, 0, curr)
draw(pic, target_tree.root, 0, WIDTH / 2, curr)
media.show(pic)
# Ask for user operations until the game tree and target tree are the
# same.
while game_tree != target_tree:
curr = process_user_command(game_tree, target_tree, curr, pic)
assert bst.is_valid_tree(game_tree.root)
