salesman problem in csharp

main.cs
using System;

class Salesman
{
    static int[,] distances = { { 0, 10, 15, 20 },
                                { 10, 0, 35, 25 },
                                { 15, 35, 0, 30 },
                                { 20, 25, 30, 0 } };

    static int[,] memo;

    static int tsp(int mask, int pos)
    {
        if (mask == (1 << distances.GetLength(0)) - 1)
            return distances[pos, 0];

        if (memo[mask, pos] != -1)
            return memo[mask, pos];

        int res = int.MaxValue;
        for (int next = 0; next < distances.GetLength(0); next++)
        {
            if ((mask & (1 << next)) == 0)
            {
                int newMask = mask | (1 << next);
                int route = distances[pos, next] + tsp(newMask, next);
                res = Math.Min(res, route);
            }
        }

        memo[mask, pos] = res;
        return res;
    }

    static void Main()
    {
        memo = new int[1 << distances.GetLength(0), distances.GetLength(0)];
        for (int i = 0; i < memo.GetLength(0); i++)
            for (int j = 0; j < memo.GetLength(1); j++)
                memo[i, j] = -1;
        Console.WriteLine(tsp(1, 0));
        Console.ReadLine();
    }
}
1208 chars
45 lines