public static HashMap<Integer, Integer[]> createRating(){
		HashMap<Integer, Integer[]> map = new HashMap<Integer, Integer[]>();
		for(int i = 0; i < train.size(); i++){
			if(!map.containsKey(Integer.parseInt(train.get(i)[0]))){
				Integer[] ratings = new Integer[movieNumber];
				for(int j = 0; j < ratings.length; j++)
					ratings[j] = 0;
				map.put(Integer.parseInt(train.get(i)[0]), ratings);
			}
			Integer[] sublist = map.get(Integer.parseInt(train.get(i)[0]));
			sublist[Integer.parseInt(train.get(i)[1]) - 1] = Integer.parseInt(train.get(i)[2]);
		}
		return map;
	}