MovieMania

Main.java

import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws FileNotFoundException {
		File file = new File("b.in");
		Scanner scan = new Scanner(file);
		List<String> list = new ArrayList<String>();
		int loop = scan.nextInt();
		for (int i = 1; i <= loop; i++) {
			System.out.println("case_" + i);
			int line = scan.nextInt();
			int words = scan.nextInt();
			for (int j = 1; j <= words; j++) {
				list.add(scan.next());
			}
			scan.nextLine(); // Flush `\n`
			
			HashSet<String> recommend = new HashSet<String>();
			HashSet<String> unrecommend = new HashSet<String>();
			Map<String, HashSet<String>> rec = new HashMap<String, HashSet<String>>();
			Map<String, HashSet<String>> unrec = new HashMap<String, HashSet<String>>();
			
			// Contains all Movie
			for (int k = 0; k < line; k++) {
				String str = scan.nextLine();
				for (int j = 0; j < list.size(); j++) {
					HashSet<String> cache;
					if (str.indexOf(list.get(j)) < 0) 
						unrecommend.add(str.split(" ")[0]);
					else 
						recommend.add(str.split(" ")[0]);
					if (rec.containsKey(list.get(j))) {
						cache = rec.get(list.get(j));
						cache.addAll(recommend);
						cache = unrec.get(list.get(j));
						cache.addAll(unrecommend);
					} else {
						rec.put(list.get(j), new HashSet<String>(recommend));
						unrec.put(list.get(j), new HashSet<String>(unrecommend));
					}
					unrecommend.clear();
					recommend.clear();
				}
			}
			
			// Print Result
			List<String> k = new ArrayList<String>(unrec.keySet());
			Collections.sort(k);
			for(String key : k) {
				System.out.print(key + "-");
				if(rec.get(key).size() == 0 || rec.get(key).size() == 1 || rec.get(key).size() == line) System.out.print("null");
				else {
					List<String> sort = new ArrayList<String>(unrec.get(key));
					Collections.sort(sort);
					for(String movie : sort) {
						System.out.print(movie + " ");
					}
				}
				System.out.println();
			}
		}
	}
}

Test Case (FILE : b.in)

3
4 6 Bat Ant Dog Egg Fat Cat
Avatar Bat Ant Cat Egg
Transformer Cat Egg Ant Dog Bat
Inception Dog Egg Ant Cat
HarryPotter Fat Ant Bat Dog
5 6 Cat Bat Dog Fat Egg Ant
Avatar Ant Dog Fat
Transformer Bat Fat Ant
Inception Cat Bat
HarryPotter Dog Cat
T2 Egg Cat Fat
4 6 Bat Fat Ant Egg Cat Dog
Avatar Egg Fat
Transformer Ant Bat Dog
Inception Bat Ant Cat Dog
T2 Dog Bat Ant Cat

OUTPUT (std.out)

case_1
Ant-null
Bat-Inception
Cat-HarryPotter
Dog-Avatar
Egg-HarryPotter
Fat-null
case_2
Ant-HarryPotter Inception T2
Bat-Avatar HarryPotter T2
Cat-Avatar Transformer
Dog-Inception T2 Transformer
Egg-null
Fat-HarryPotter Inception
case_3
Ant-Avatar
Bat-Avatar
Cat-Avatar Transformer
Dog-Avatar
Egg-null
Fat-null