def _traverse_level_order_iterative(self, start_node, visit):
"""Traverse this binary tree with iterative level-order traversal (BFS).
Start at the given node and visit each node with the given function.
TODO: Running time: on each node we perform 3 operations, assumming
each operations on each node take O(1) it takes 3 * O(n) for the tree to be traversed
TODO: Memory usage: O(2^h) would be the worst running time if we have
two children for every parent, but that might not be the case. Considering
that a parent might have one child O(n) would be a better estimate."""
# TODO: Create queue to store nodes not yet traversed in level-order
q = ArrayQueue()
# TODO: Enqueue given starting node
q.enqueue(start_node)
# TODO: Loop until queue is empty
while q.length() != 0:
# TODO: Dequeue node at front of queue
q.front()
node = q.dequeue()
# TODO: Visit this node's data with given function
visit(node.data)
# TODO: Enqueue this node's left child, if it exists
if node.left:
q.enqueue(node.left)
# TODO: Enqueue this node's right child, if it exists
if node.right:
q.enqueue(node.right)
def _traverse_level_order_iterative(self, start_node, visit):
"""Traverse this binary tree with iterative level-order traversal (BFS).
Start at the given node and visit each node with the given function.
TODO: Running time: ??? Why and under what conditions?
TODO: Memory usage: ??? Why and under what conditions?"""
# TODO: Create queue to store nodes not yet traversed in level-order
queue = ArrayQueue()
# TODO: Enqueue given starting node
queue.enqueue(start_node)
# TODO: Loop until queue is empty
while queue.length() != 0:
# TODO: Dequeue node at front of queue
node = queue.front()
queue.dequeue()
# TODO: Visit this node's data with given function
visit(node.data)
# TODO: Enqueue this node's left child, if it exists
if node.left is not None:
queue.enqueue(node.left)
# TODO: Enqueue this node's right child, if it exists
if node.right is not None:
queue.enqueue(node.right)