Problem:
Score : 400 points

Problem Statement

There are N towns in the State of Atcoder, connected by M bidirectional roads.

The i-th road connects Town A_i and B_i and has a length of C_i.

Joisino is visiting R towns in the state, r_1,r_2,..,r_R (not necessarily in this order).

She will fly to the first town she visits, and fly back from the last town she visits, but for the rest of the trip she will have to travel by road.

If she visits the towns in the order that minimizes the distance traveled by road, what will that distance be?

Constraints

2≤N≤200

1≤M≤N×(N-1)/2

2≤R≤min(8,N) (min(8,N) is the smaller of 8 and N.)

r_i≠r_j (i≠j)

1≤A_i,B_i≤N, A_i≠B_i

(A_i,B_i)≠(A_j,B_j),(A_i,B_i)≠(B_j,A_j) (i≠j)

1≤C_i≤100000

Every town can be reached from every town by road.

All input values are integers.

Input

Input is given from Standard Input in the following format:

N M R
r_1 ... r_R
A_1 B_1 C_1
:
A_M B_M C_M

Output

Print the distance traveled by road if Joisino visits the towns in the order that minimizes it.

Sample Input 1

3 3 3
1 2 3
1 2 1
2 3 1
3 1 4

Sample Output 1

2

For example, if she visits the towns in the order of 1, 2, 3, the distance traveled will be 2, which is the minimum possible.

Sample Input 2

3 3 2
1 3
2 3 2
1 3 6
1 2 2

Sample Output 2

4

The shortest distance between Towns 1 and 3 is 4. Thus, whether she visits Town 1 or 3 first, the distance traveled will be 4.

Sample Input 3

4 6 3
2 3 4
1 2 4
2 3 3
4 3 1
1 4 1
4 2 2
3 1 6

Sample Output 3

3

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using static Atcoder;
using System.Threading.Tasks;
using System.ComponentModel;

public class Hello
{
    private const int INF = 1000000007;
    public static void Main()
    {
        int[] NMR = IntLine();
        int N = NMR[0], M = NMR[1], R = NMR[2];
        int[] rR = IntLine().Select(v => v - 1).ToArray();
        int[,] Edge = new int[N, N];
        for (int i = 0; i < N; i++)
            for (int j = 0; j < N; j++)
                Edge[i, j] = (i == j ? 0 : INF);
        for (int i = 0; i < M; i++)
        {
            int[] box = IntLine();
            Edge[box[0] - 1, box[1] - 1] = Math.Min(Edge[box[0] - 1, box[1] - 1], box[2]);
            Edge[box[1] - 1, box[0] - 1] = Math.Min(Edge[box[1] - 1, box[0] - 1], box[2]);
        }
        //WF
        for (int i = 0; i < N; i++)
            for (int j = 0; j < N; j++)
                for (int k = 0; k < N; k++)
                    Edge[j, k] = Math.Min(Edge[j, k], Edge[j, i] + Edge[i, k]);

        Permutation p = new Permutation(rR.ToList());
        p.PermList = new List<List<int>>();
        p.Calc(new List<int>());
        long ans = INF;
        foreach (var l in p.PermList)
        {
            long b = 0;
            for (int i = 1; i < R; i++)
            {
                b += Edge[l[i - 1], l[i]];
            }
            ans = Math.Min(ans, b);
        }
        Console.WriteLine(ans);
    }
}

public class Permutation
{
    private static List<int> line;
    public List<List<int>> PermList { get; set; }

    public Permutation(List<int> list) { line = new List<int>(list); }

    public void Calc(List<int> list)
    {
        if (list.Count == line.Count())
        {
            PermList.Add(list);
            return;
        }
        foreach (int i in line)
        {
            if (!list.Contains(i))
            {
                List<int> nextlist = new List<int>(list);
                nextlist.Add(i);
                Calc(nextlist);
            }
        }
    }

    public void Draw()
    {
        foreach (var l in PermList)
        {
            l.ForEach(v => Console.Write(v + " "));
            Console.WriteLine();
        }
    }
}

public class Atcoder
{
    public static void Swap<T>(ref T a, ref T b)
    {
        var t = a;
        a = b;
        b = t;
    }
    public static int GCD(int a, int b)
    {
        if (a < b) Swap(ref a, ref b);
        int d = a % b;
        while (b != 0)
        {
            d = a % b;
            a = b;
            b = d;
        }
        return a;
    }
    public static long LCM(int a, int b)
    {
        return (long)a * b / GCD(a, b);
    }
    public static string StrReverce(string s)
    {
        return new string(s.Reverse().ToArray());
    }
    public static int IntRead()
    {
        return int.Parse(Console.ReadLine());
    }
    public static bool IsPrime(int n)
    {
        if (n < 2) return false;
        if (n == 2) return true;
        if (n % 2 == 0) return false;

        //double sqrtNum = Math.Sqrt(n);
        for (int i = 3; i < n; i += 2)
        {
            if (n % i == 0) return false;
        }
        return true;
    }
    public static string[] SpRead(char c)
    {
        return Console.ReadLine().Split(c);
    }
    public static long[] LSRead()
    {
        return Console.ReadLine().Split(' ').Select(long.Parse).ToArray();
    }
    public static long Combination(int n, int r)
    {
        if (n == r) return 1;
        return
            Enumerable.Range((n - r + 1), r).ToList().Aggregate((now, next) => now * next) /
            Enumerable.Range(1, r).ToList().Aggregate((now, next) => now * next);
    }
    public static long Permutation(int n, int r)
    {
        if (n == r) return 1;
        return
            Enumerable.Range((n - r), r).ToList().Aggregate((now, next) => now * next);
    }
    public static long LongRead()
    {
        return long.Parse(Console.ReadLine());
    }
    public static long[] LongLine()
    {
        return Console.ReadLine().Split(' ').Select(long.Parse).ToArray();
    }
    public static int[] IntLine()
    {
        return Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
    }
}