BFS

sample.py

# Using a Python dictionary to act as an adjacency list
graph = {
    'A' : ['B','C'],
    'B' : ['D', 'E'],
    'C' : ['F'],
    'D' : [],
    'E' : ['F'],
    'F' : []
}


def dfs(_visited, graph, node):
    if node not in _visited:
        _visited.add(node)
        print(node)
        for neighbour in graph[node]:
            dfs(_visited, graph, neighbour)

# Driver Code
# source = input("Enter the source")
# dfs(_visited, graph, source)

queue = []     #Initialize a queue

def bfs(visited, graph, node):
  visited.append(node)
  queue.append(node)

  while queue:
    s = queue.pop(0) 
    print (s, end = " ") 

    for neighbour in graph[s]:        
        if neighbour not in visited:
            visited.append(neighbour)
            queue.append(neighbour)

# Driver Code
# source = input("Enter the source")
# bfs(visited, graph, source)

while True:
    print("\n1-BREADTH FIRST SEARCH")
    print("2-DEPTH FIRST SEARCH")
    print("0-EXIT")
    ch = int(input("ENTER YOUR CHOICE-: \n"))
    if ch == 0:
        print("EXIT")
        break;
    if ch==1:
        source = input("ENTER THE 1 SOURCE: ")
        bfs([], graph, source )
    if ch==2:
        source = input("ENTER THE 2 SOURCE: ")
        dfs(set(), graph, source)