from binary_tree import BinaryTree
def bfs(tree, val):
"""
Returns whether a node is present in a tree using breadth-first search
"""
deque = deque([tree.root])
while deque:
current = deque.popleft()
if current.data == val:
return True
else:
if current.left:
deque.append(current.left)
if current.right:
deque.append(current.right)
return False
if __name__ == '__main__':
b = BinaryTree.factory(1)
b.insert(2)
b.insert(3)
assert bfs(b, 1) is True
assert bfs(b, 3) is True
assert bfs(b, 4) is False
print 'All tests pass!'
