Cod sursa(job #3200333)

Utilizator biancalautaruBianca Lautaru biancalautaru Data 4 februarie 2024 13:09:19
Problema Ubuntzei Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 1.9 kb
#include <fstream>
#include <vector>
#include <queue>
#define INF 2000000001
#define NMAX 2001
#define KMAX 17
using namespace std;
ifstream fin("ubuntzei.in");
ofstream fout("ubuntzei.out");
int n,m,k,x,y,c,nr,mini,v[KMAX],d[KMAX][NMAX],dp[KMAX][1<<KMAX];
bool viz[NMAX];
vector<pair<int,int>> l[NMAX];
priority_queue<pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> pq;

void dijkstra(int poz) {
    for (int i=1;i<=n;i++) {
        d[poz][i]=INF;
        viz[i]=0;
    }
    d[poz][v[poz]]=0;
    pq.push({0,v[poz]});
    while (!pq.empty()) {
        int nod=pq.top().second;
        pq.pop();
        if (viz[nod]==1)
            continue;
        viz[nod]=1;
        for (int i=0;i<l[nod].size();i++) {
            int vec=l[nod][i].first;
            int cost=l[nod][i].second;
            if (d[poz][nod]+cost<d[poz][vec]) {
                d[poz][vec]=d[poz][nod]+cost;
                pq.push({d[poz][vec],vec});
            }
        }
    }
}

int main() {
    fin>>n>>m>>k;
    for (int i=1;i<=k;i++)
        fin>>v[i];
    v[++k]=1;
    while (m--) {
        fin>>x>>y>>c;
        l[x].push_back({y,c});
        l[y].push_back({x,c});
    }
    for (int i=1;i<=k;i++)
        dijkstra(i);
    if (k==1) {
        fout<<d[1][n];
        return 0;
    }
    k--;
    nr=(1<<k)-1;
    for (int i=1;i<=k;i++) {
        for (int j=1;j<=nr;j++)
            dp[i][j]=INF;
        dp[i][1<<(i-1)]=d[i][1];
    }
    for (int st=1;st<=nr;st++)
        for (int i=1;i<=k;i++)
            if (dp[i][st]!=INF)
                for (int j=1;j<=k;j++)
                    if (i!=j && ((st>>(j-1))&1)==0) {
                        int nxt=st+(1<<(j-1));
                        dp[j][nxt]=min(dp[j][nxt],dp[i][st]+d[i][v[j]]);
                    }
    mini=INF;
    for (int i=1;i<=k;i++)
        mini=min(mini,dp[i][nr]+d[i][n]);
    fout<<mini;
    return 0;
}