package lab1;

import org.jacop.constraints.*;
import org.jacop.core.*;
import org.jacop.search.*;

public class Photo2 {
	public static void main(String[] args) {

		int n = 9;
		int n_prefs = 17;
		int[][] prefs = {{1,3}, {1,5}, {1,8},
		{2,5}, {2,9}, {3,4}, {3,5}, {4,1},
		{4,5}, {5,6}, {5,1}, {6,1}, {6,9},
		{7,3}, {7,8}, {8,9}, {8,7}};

		int n2 = 11;
		int n_prefs2 = 20;
		int[][] prefs2 = {{1,3}, {1,5}, {2,5},
		{2,8}, {2,9}, {3,4}, {3,5}, {4,1},
		{4,5}, {4,6}, {5,1}, {6,1}, {6,9},
		{7,3}, {7,5}, {8,9}, {8,7}, {8,10},
		{9, 11}, {10, 11}};

		int n3 = 15;
		int n_prefs3 = 20;
		int[][] prefs3 = {{1,3}, {1,5}, {2,5},
		{2,8}, {2,9}, {3,4}, {3,5}, {4,1},
		{4,15}, {4,13}, {5,1}, {6,10}, {6,9},
		{7,3}, {7,5}, {8,9}, {8,7}, {8,14},
		{9, 13}, {10, 11}};


		photo(n2, prefs2);

	}

	private static void photo(int n, int[][] prefs){

		Store store = new Store();
		//Create a list of persons and don't let them stand in the same spot
		IntVar[] ps = new IntVar[n];
		for(int i = 0; i < n; i++){
			ps[i] = new IntVar(store, "p"+(i+1), 0, n); //index for each person, value for their place
		}
		store.impose(new Alldifferent(ps));


		BooleanVar[] costs = new BooleanVar[prefs.length];

		for(int i = 0; i < prefs.length; i++){

			costs[i] = new BooleanVar(store);
			//index of the two people in this preference, adjusted for 0 indexing
			int person1 = prefs[i][0] - 1;
			int person2 = prefs[i][1] - 1;

			//Create FDV for distance between persons
			IntVar distance = new IntVar(store, 0, n);
			store.impose(new Distance(ps[person1], ps[person2], distance));

			//if distance is greater than 1, costs[i] is 1
			store.impose(new Reified(new XgtC(distance, 1) , costs[i]));
		}
		IntVar cost = new IntVar(store, "cost", 0, prefs.length);
		store.impose(new SumBool(costs, "==", cost));

		Search<IntVar> search = new DepthFirstSearch<IntVar>();
        SelectChoicePoint<IntVar> select =
            new InputOrderSelect<IntVar>(store, ps,
                                         new IndomainMin<IntVar>());
        boolean result = search.labeling(store, select, cost);

        //some printing stuff. This seems pretty stupid
        if(result){
        	String costString = cost.toString();
        	char s = costString.charAt(costString.length() - 1);
        	int i = Integer.parseInt(String.valueOf(s));
        	System.out.println(prefs.length - i + " of " + prefs.length + " preferences satisfied");
        } else {
        	System.out.println("Nein");
        }

	}


}