BFS (Breadth First Search)

Solution

def bfs(graph, visited):
  queue = []
  queue.append("a")
  visited["a"] = True
  while queue:
    temp = queue.pop(0)
    print(temp)
    for item in graph[temp]:
      if not visited.get(item):
        queue.append(item)
        visited[item] = True


node = ["a", "b", "c", "d", "e", "g", "f"]
edges = [["a", "b"], ["b", "c"], ["b", "e"], ["c", "d"], ["c", "e"],
         ["e", "g"], ["f", "f"]]

graph = {}
visited = {}

for i in node:
  graph[i] = []

for (u, v) in edges:
  graph[u].append(v)
  graph[v].append(u)

bfs(graph, visited)