Population.java

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Random;
import java.util.Scanner;


public class Population {
    private static Random rd = new Random(0);
    private static final double Pm = 0.7;
    private static final double Pc = 0.95;
    private static final double R_OFFSPRING = 0.6;
    private static final int N_I = 1000000;
    private static final int LEN_GEN = 51;
    private ArrayList<Individual> l = new ArrayList<Individual>();

    public static void main(String[] args) throws FileNotFoundException {
        Population p = new Population();
        p.Init();
        final int GENERATION = 35;
        for (int i = 1; i <= GENERATION; i++) {
            ArrayList<Individual> l_OffSpring = new ArrayList<Individual>();
            ArrayList<Individual> parent_selected = p.parent_Selection();
            int count = 0;
            for (int j = 0; j <= parent_selected.size() - 1; j++) {
                for (int q = j + 1; q < parent_selected.size(); q++) {
                    if (count == (int) (R_OFFSPRING * N_I)) {
                        break;
                    } else {
                        if (rd.nextDouble() < Pc) {
                            count += 2;
                            ArrayList<Individual> rs = new ArrayList<>();
                            rs = parent_selected.get(j).PMX_crossOver(parent_selected.get(q), rd);
                            if (rd.nextDouble() < Pm) {
                                rs.get(0).mutation(rd);
                            }
                            if (rd.nextDouble() < Pm) {
                                rs.get(1).mutation(rd);
                            }
                            l_OffSpring.add(rs.get(0));
                            l_OffSpring.add(rs.get(1));
                        }
                    }
                }
            }
            p.elitism(l_OffSpring);
            p.sort_Rank();
            System.out.println(p.l.get(0).fitness);
            System.out.println(Arrays.toString(p.l.get(0).genes));
        }
        // System.out.println(p.l.get(0).fitness);
        // System.out.println(Arrays.toString(p.l.get(0).genes));
    }

    public void Init() throws FileNotFoundException {

        Scanner sc = new Scanner(new BufferedReader(new FileReader("eli51_d.txt")));
        Individual.COST = new int[LEN_GEN + 1][LEN_GEN + 1];
        while (sc.hasNextLine()) {
            for (int i = 1; i <= LEN_GEN; i++) {
                String[] line = sc.nextLine().trim().split(" ");
                for (int j = 0; j < line.length; j++) {
                    Individual.COST[i][j + 1] = Integer.parseInt(line[j]);
                }
            }
        }

        ArrayList<Integer> genes = new ArrayList<>();
        int[] copy_genes = new int[LEN_GEN + 1];
        for (int i = 1; i <= LEN_GEN; i++) {
            genes.add(i);
        }
        for (int i = 1; i <= LEN_GEN; i++) {
            copy_genes[i] = genes.get(i - 1);
        }

        l.add(new Individual(LEN_GEN, copy_genes));

        for (int j = 2; j <= N_I; j++) {
            Collections.shuffle(genes, rd);
            for (int i = 1; i <= LEN_GEN; i++) {
                copy_genes[i] = genes.get(i - 1);
            }
            l.add(new Individual(LEN_GEN, copy_genes));
        }

        sort_Rank();
    }

    public void sort_Rank() {
        Collections.sort(l, Collections.reverseOrder());
    }

    public ArrayList<Individual> parent_Selection() {
        ArrayList<Individual> parent_selected = new ArrayList<>();
        int n_idv_best = (int) (N_I * 0.2 * 0.1);
        int n_idv_worst = (int) (N_I * 0.2 * 0.9);
        for (int i = 0; i < n_idv_best; i++) {
            parent_selected.add(this.l.get(i));
        }

        for (int i = this.l.size() - n_idv_worst; i < this.l.size(); i++) {
            parent_selected.add(this.l.get(i));

        }

        return parent_selected;
    }

    public void elitism(ArrayList<Individual> offSpring_l) {
        for (int i = 0; i < offSpring_l.size(); i++) {
            int idx = this.l.size() - 1;
            this.l.remove(idx);
        }
        for (int i = 0; i < offSpring_l.size(); i++) {
            this.l.add(offSpring_l.get(i));
        }
    }

}