Breadth First Search (BFS) Algorithms
Breadth First Search (BFS) Pseudocode
The below pseudocode outlines the Breadth-First Search algorithm, here the problem represents the pathfinding problem.
BREATH-FIRST-SEARCH(problem) returns a solution node or failure
node ← NODE(problem.INITIAL)
if problem.IS-GOAL(node.STATE) then return node
frontier ← a FIFO queue, initialized with node
reached ← {problem.INITIAL}
while not IS-EMPTY(frontier) do
node ← POP(frontier)
for each child in EXPAND(problem, node) do
s ← child.STATE
if problem.IS-GOAL(s) then return child
if s is not in reached then
add s to reached
add child to frontier
return failure
BFS Algorithms Implementation using Python
The breadth_first_search function is responsible for implementing the BFS algorithm for pathfinding. As we have seen earlier, the BFS algorithm starts with the initial state and then it visits the neighboring states in a breadth-first manner until the goal state is found or all reachable states are explored. It maintains the FIFO queue called frontier which stores the nodes that are visited. It also uses the set called reached to keep track of the visited states and avoid revisiting them.
def breadth_first_search(problem):
node = Node(problem.initial)
if problem.is_goal(node.state):
return node
frontier = deque([node])
reached = {problem.initial}
while frontier:
node = frontier.popleft()
for child in problem.expand(node):
s = child.state
if problem.is_goal(s):
return child
if s not in reached:
reached.add(s)
frontier.append(child)
return None
Breadth First Search (BFS) for Artificial Intelligence
In artificial intelligence, the Breadth-First Search (BFS) algorithm is an essential tool for exploring and navigating various problem spaces. By systematically traversing graph or tree structures, BFS solves tasks such as pathfinding, network routing, and puzzle solving. This article probes into the core concepts of BFS, its algorithms, and practical applications in AI.
Table of Content
- What is Breadth-First Search?
- Key characteristics of BFS
- Breadth First Search (BFS) Algorithms
- How Breadth-First Search can help in Robot Pathfinding
- Practical Implementations of BFS in Pathfinding of Robots
- Conclusion
- FAQs on Breadth First Search (BFS) for Artificial Intelligence