Exemplo n.º 1
0
 private List<string> Visit(string sourceUser, string destinationUser, UserVisitedList visited)
 {
     visited.Visit(sourceUser);
     FriendDictionary friendsOfSource = userPathRepository.GetFriendsOf(sourceUser);
     if (friendsOfSource.Contains(destinationUser))
     {
         // we found it.
         return new List<string> { sourceUser, destinationUser };
     }
     // get highest-friendcount friend (that we have not yet visited) and see if that leads to the destination.
     // if not, try the Nth friend, until there are no more friends, then give up on this branch.
     foreach(TwitterUser friend in friendsOfSource.Friends)
     {
         if (!visited.Visited(friend.Name))
         {
             List<string> searchResult = Visit(friend.Name, destinationUser, visited);
             if (searchResult != null)
             {
                 // this branch was successful.  searchResult already contains friend.Name, so append our name to the head of the list.
                 searchResult.Insert(0, sourceUser);
                 return searchResult;
             }
         }
     }
     // this branch was not successful, no friends of sourceUser matched destinationUser.
     return new List<string>();
 }
Exemplo n.º 2
0
        public IEnumerable<string> FindPath(string sourceUser, string destinationUser)
        {
            if (sourceUser == destinationUser)
                return new List<string> {sourceUser};

            var friendsVisited = new UserVisitedList();
            return Visit(sourceUser, destinationUser, friendsVisited);
        }