Cod sursa(job #2544466)

Utilizator victorzarzuZarzu Victor victorzarzu Data 12 februarie 2020 09:03:41
Problema Ubuntzei Scor 0
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 2.2 kb
#include <bits/stdc++.h>
#define oo 0x3f3f3f3f

using namespace std;
ifstream f("ubuntzei.in");
ofstream h("ubuntzei.out");
typedef long long ll;
int n,m,k,x,y,cost,mask2;
vector<pair<int,int>> G[2001];
ll dist[20][2001];
ll dp[33000][20];
int orase[2001];
ll ans = oo;
void dijkstra(int nod,ll d[])
{
    for(int i = 0;i <= n;++i)
        d[i] = oo;
    d[nod] = 0;
    set<pair<int,int>> h;
    h.insert(make_pair(0,nod));
    while(!h.empty())
    {
        int node = h.begin() -> second;
        int di = h.begin() -> first;
        h.erase(h.begin());

        for(vector<pair<int,int>>::iterator it = G[node].begin();it != G[node].end();++it)
        {
            int to = it -> first;
            int cost = it -> second;
            if(d[to] > d[node] + cost)
            {
                if(d[to] != oo)
                    h.erase(h.find(make_pair(d[to],to)));
                d[to] = d[node] + cost;
                h.insert(make_pair(d[to],to));
            }
        }
    }
}

void Read()
{
    f>>n>>m;
    f>>k;
    for(int i = 0;i < k;++i)
        f>>orase[i];
    for(int i = 1;i <= m;++i)
    {
        f>>x>>y>>cost;
        G[x].push_back(make_pair(y,cost));
        G[y].push_back(make_pair(x,cost));
    }
}


void Solve()
{
    for(int i = 0;i < k;++i)
        dijkstra(orase[i],dist[i]);
    dijkstra(1,dist[k]);
    if(!k)
    {
        cout<<dist[k][n]<<'\n';
        return;
    }
    for(int mask = 0;mask < (1 << k);++mask)
        for(int pos = 0;pos < k;++pos)
            if(mask & (1 << pos))
            {
                ll mask2 = mask ^ (1 << pos);
                if(mask2 == 0)
                {
                    dp[mask][pos] = dist[k][orase[pos]];
                    break;
                }
                dp[mask][pos] = oo;
                for(int i = 0;i < pos;++i)
                    if(mask2 & (1 << i))
                        dp[mask][pos] = min(dp[mask][pos],dp[mask2][i] + dist[i][orase[pos]]);
            }
    ll mask = (1 << k) - 1;
    for(int i = 0;i < k;++i)
        ans = min(ans,dp[mask][i] + dist[i][n]);
    h<<ans;
    h.close();
}

int main()
{
    Read();
    Solve();
    return 0;
}