Cod sursa(job #2230820)

Utilizator AndreiTurcasTurcas Andrei AndreiTurcas Data 11 august 2018 17:48:16
Problema Ubuntzei Scor 80
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.9 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#define lim 2000
#define oo 0x3f3f3f3f
#define mp make_pair
using namespace std;

ifstream f("ubuntzei.in");
ofstream g("ubuntzei.out");

int n, m, k, go[lim+1], dp[1<<15][16], Dist[16][lim+1], answer;
vector<pair<int,int> > G[lim+1];
queue<int> Q;

void Read()
{
    f >> n >> m;
    f >> k;
    go[0] = 1;
    for(int i = 1; i <= k; ++i)
    {
        int t;
        f >> t;
        go[i] = t;
    }
    for(int i = 0; i <= k; ++i)
        for(int j = 1; j <= n; ++j)
            Dist[i][j] = oo;
    for(int i = 1; i <= m; ++i)
    {
        int x, y, c;
        f >> x >> y >> c;
        G[x].push_back(mp(y, c));
        G[y].push_back(mp(x, c));
    }
}

void BelFord(int src)
{
    Dist[src][go[src]] = 0;
    Q.push(go[src]);
    while(!Q.empty())
    {
        int v = Q.front();
        Q.pop();
        for(vector<pair<int,int> > :: iterator it = G[v].begin(); it != G[v].end(); ++it)
        {
            int v2 = it->first, d = it->second;
            if(Dist[src][v2] > Dist[src][v] + d)
            {
                Dist[src][v2] = Dist[src][v] + d;
                Q.push(v2);
            }
        }
    }
}

void Dp()
{
    for(int i = 1; i <= k; ++i)
        dp[1<<(i-1)][i] = Dist[0][go[i]];
    for(int s = 1; s < 1<<k; ++s)
        for(int i = 1; i <= k; ++i)
            if(s != 1<<(i-1) && s & 1<<(i-1))
            {
            dp[s][i] = oo;
            for(int j = 1; j <= k; ++j)
                if(i != j && s & 1<<(j-1))
                    dp[s][i] = min(dp[s][i], dp[s-(1<<(i-1))][j] + Dist[j][go[i]]);
            }
}

int main()
{
    Read();
    for(int i = 0; i <= k; ++i)
    BelFord(i);
    Dp();
    answer = oo;
    int s = (1<<k)-1;
    for(int i = 1; i <= k; ++i)
        answer = min(answer, dp[s][i] + Dist[i][n]);
    g << answer;
}