Коммивояжер (динамика по битовым маскам)

import java.io.File;
import java.io.FileNotFoundException;
import java.util.*;

import static java.lang.Integer.MAX_VALUE;
import static java.lang.Integer.reverse;
import static java.lang.Math.min;

public class MySolution
{
    public static void main(String[] args)
         throws FileNotFoundException {
        Scanner in = new Scanner(new File("salesman2.in"));//new File("f.in")

        int n = in.nextInt();

        int[][] a = new int[n][n];

        for(int i = 0; i < n; i++)
        {
            for (int j = 0; j < n; j++)
            {
                a[i][j] = in.nextInt();
            }
        }
        int[][] d = new int[1 << n][n];
        int[][] p  = new int[1 << n][n];
        for (int mask = 0; mask < (1 << n); mask++)
        {
            for (int i = 0; i < n; i++)
            {
                d[mask][i] = MAX_VALUE;
            }
        }

        d[0][0] = 0;

        for (int mask = 0; mask < (1 << n); mask++)
        {
            for (int i = 0; i < n; i++)
            {
                if (d[mask][i] == MAX_VALUE)
                    continue;

                for (int j = 0; j < n; j++)
                {
                    if ((mask & (1 << j)) == 0) // в маске нет города j
                    {
                        if (d[mask][i] + a[i][j] < d[mask ^ (1 << j)][j]) {
                            d[mask ^ (1 << j)][j] = d[mask][i] + a[i][j];
                            p[mask ^ (1 << j)][j] = i;
                        }
                    }
                }
            }
        }

        System.out.println(d[(1 << n) - 1][0]);
        System.out.println();
        int[] lp = new int[n];

        int i = 0;
        int mask = (1 << n) - 1;
        int last = 0;
        do
        {
            lp[i++] = p[mask][last];
            int maskPrev = mask;
            mask = mask ^ (1 << last);
            last = p[maskPrev][last];
        } while (mask != 0);

        if (lp[0] < lp[n - 2])
        {
            System.out.print(0 + " " );
            for (int j = 0; j < n - 1; j ++)
            {
                System.out.print(lp[j] + " " );
            }
        }
        else
        {
            for (int j = n - 1; j >= 0; j--)
            {
                System.out.print(lp[j] + " ");
            }
        }
}