アルゴリズム-広さ優先検索

from collections import deque

graph={
     }
graph["you"]=["alice","bob","claire"]
graph["bob"]=["anuj","peggy"]
graph["alice"]=["peggy"]
graph["claire"]=["thom","jonny"]
graph["anuj"]=[]
graph["peggy"]=[]
graph["thom"]=[]
graph["jonny"]=[]

print(graph)

def person_is_seller(name):
    return name[-1]=='m'

def search(name):
    search_queue=deque()
    search_queue+=graph[name]
    searched=[]
    while search_queue:
        person=search_queue.popleft()
        if not person in searched:
            if person_is_seller(person):
                print('{} is a mango seller'.format(person))
                return True
            else:
                search_queue+=graph[person]
                searched.append(person)
    return False

search('you')