/*
* Implement a function to return top rated movies in the network of movies
* reachable from the current movie
* eg: A(Rating 1.2)
* / \
* B(2.4) C(3.6)
* \ /
* D(4.8)
* In the above example edges represent similarity and the number is rating.
* getMovieRecommendations(A,2)should return C and D (sorting order doesn't matter so it can also return D and C)
* getMovieRecommendations(A,4) should return A, B, C, D (it can also return these in any order eg: B,C,D,A)
* getMovieRecommendations(A,1) should return D. Note distance from A to D doesn't matter,
* return the highest rated.
*
* @param movie
* @param numTopRatedSimilarMovies
* number of movies we want to return
* @return List of top rated similar movies
*/
public static IList<Movie> getMovieRecommendations(Movie movie, int numTopRatedSimilarMovies)
{
int movieCount = 0;
IList<Movie> OrderedMovieList = new List<Movie>();
if (numTopRatedSimilarMovies <= 0)
{
Console.WriteLine("Only positive numbers are expected.");
return OrderedMovieList;
}
SortedDictionary<Movie, float> movieOrder = new SortedDictionary<Movie, float>();
var visited = new HashSet<Movie>();
Stack<Movie> stack = new Stack<Movie>();
stack.Push(movie);
while (stack.Count != 0)
{
Movie current = stack.Pop();
IList<Movie> movieList = current.getSimilarMovies();
if (!visited.Add(current))
continue;
if (!movieOrder.ContainsKey(current))
movieOrder.Add(current, current.getRating());
foreach (var movei in movieList)
stack.Push(movei);
}
foreach (Movie item in (movieOrder.Keys.Reverse()))
{
if(movieCount < numTopRatedSimilarMovies)
{
OrderedMovieList.Add(item);
movieCount++;
}
//Console.WriteLine("{0}={1}", item.getId(), item.getRating());
}
return OrderedMovieList;
}
public void addSimilarMovie(Movie movie)
{
similarMovies.Add(movie);
movie.similarMovies.Add(this);
}
static void Main(string[] args)
{
Movie movieA = new Movie(1, 1.2f);
Movie movieB = new Movie(2, 2.4f);
Movie movieC = new Movie(3, 3.6f);
Movie movieD = new Movie(4, 4.8f);
movieA.addSimilarMovie(movieB);
movieA.addSimilarMovie(movieC);
movieA.addSimilarMovie(movieD);
IList<Movie> movieList1 = getMovieRecommendations(movieA, 0);
IList<Movie> movieList2 = getMovieRecommendations(movieA, 2);
//IList<Movie> movieList3 = getMovieRecommendations(movieA, 3);
foreach (Movie mov in movieList1)
{
Console.WriteLine(mov.getId());
}
Console.ReadLine();
}