mTSP W/ Random

gistfile1.txt

import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

/**
 * Created by yasincidem on 19.3.2018.
 */
public class mTSP {
    private int numDepots;
    private int numSalesmen;
    private int cost = 0;
    private static final Random rand = new Random();
    private static final String[] cities = TurkishNetwork.cities;
    private final int[][] distance = TurkishNetwork.distance;
    private List<Integer> depots;
    private List<List<Integer>> lists;

    private final List<Integer> numbers0To80 = IntStream.range(0, 81).boxed().collect(Collectors.toList());


    public mTSP(int numDepots, int numSalesmen) {
        this.numDepots = numDepots;
        this.numSalesmen = numSalesmen;
        depots= rand.ints(0, cities.length)
                .distinct()
                .limit(numDepots)
                .boxed()
                .collect(Collectors.toList());
    }

    void randomSolution() {
        lists = toSublists(numbers0To80);
        for (final List<Integer> list : lists) {
            for (int j = 0; j < list.size() - 1; j++) {
                cost += distance[list.get(j)][list.get(j + 1)];
            }
        }
    }

    boolean validate() {
        final List<Integer> collect = lists.stream().flatMap(List::stream).distinct().collect(Collectors.toList());
        Collections.sort(collect);
        return collect.equals(IntStream.range(0, 81).boxed().collect(Collectors.toList()));
    }

    int cost() {
        return cost;
    }

    void print(boolean verbose) {
        if (verbose) {
            for (int i = 0; i < lists.size(); i++) {
                final List<Integer> list = lists.get(i);

                if ((i%numSalesmen) == 0) {
                    System.out.println( "Depot" + (i / numSalesmen + 1 )+ ": " + depots.get(i / numSalesmen));
                }
                System.out.print("  Route:"  + (i%numSalesmen + 1) + " ");

                for (int j = 0; j < list.size(); j++) {
                    if (j != 0 && j != list.size() - 1)
                        System.out.print(list.get(j) + (j != list.size() - 2 ? ", " : " " ));
                }
                System.out.println();
            }
        } else {
            for (int i = 0; i < lists.size(); i++) {
                final List<Integer> list = lists.get(i);

                if ((i%numSalesmen) == 0) {
                    System.out.println("Depot" + (i / numSalesmen + 1)+ ": " + cities[depots.get(i / numSalesmen)]);
                }
                System.out.print("  Route:" + (i%numSalesmen + 1) + " ");

                for (int j = 0; j < list.size(); j++) {
                    if (j != 0 && j != list.size() - 1)
                        System.out.print(cities[list.get(j)] + (j != list.size() - 2 ? ", " : " " ));
                }
                System.out.println();
            }
        }

    }

    private  List<List<Integer>> toSublists(List<Integer> lists) {
        Collections.shuffle(lists);
        return partition(lists, (numDepots * numSalesmen));
    }

    private  List<List<Integer>> partition(List<Integer> iterable, int partitions){
        iterable.removeAll(depots);
        List<List<Integer>> result = new ArrayList<>(partitions);
        for(int i = 0; i < partitions; i++){
            result.add(new ArrayList<>());
        }
        Iterator<Integer> iterator = iterable.iterator();
        for(int i = 0; iterator.hasNext(); i++)
            result.get(i % partitions).add(iterator.next());
        for (int i = 0; i < result.size(); i++) {
            result.get(i).add(0, depots.get(i / numSalesmen));
            result.get(i).add(result.get(i).size() , depots.get(i / numSalesmen));
        }
        return result;
    }
}