1.2 KiB
1.2 KiB
| title |
|---|
| Breadth-First Search |
Breadth-First Search
Let's first define the Tree class to be used for the implementation of the Breadth First Search algorithm.
class Tree:
def __init__(self, x):
self.val = x
self.left = None
self.right = None
The breadth first search algorithm moves from one level to another starting from the root of the tree. We will make use of a queue for this.
def bfs(root_node):
queue = [root_node]
while queue:
top_element = queue.pop()
print("Node processed: ",top_element)
if top_element.left:
queue.append(top_element.left)
if top_element.right:
queue.append(top_element.right)
We can easily modify the above code to print the level of each node as well.
def bfs(root_node):
queue = [(root_node, 0)]
while queue:
top_element, level = queue.pop()
print("Node processed: {} at level {}".format(top_element, level))
if top_element.left:
queue.append((top_element.left, level + 1))
if top_element.right:
queue.append((top_element.right, level + 1))
| Complexity | Time | Space |
|---|---|---|
| BFS | n | n |