Cod sursa(job #1609723)

Utilizator SagunistuStrimbu Alexandru Sagunistu Data 22 februarie 2016 22:58:36
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.31 kb
#include <cstdio>
#include <vector>
#include <cstring>
#include <queue>
#define inf 0x3f3f3f3f
#define nmax 200005
#define vecin second
#define cost first

using namespace std;
vector<pair<int,int> >g[nmax];
int d[nmax],n,m,viz[nmax],t[nmax];
priority_queue<pair<int,int> >q;

void citire()
{
    int x,y,c;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d%d",&x,&y,&c);
        g[x].push_back(make_pair(c,y));
        g[y].push_back(make_pair(c,x));
    }
}

void prim()
{
    int k;
    memset(d,inf,sizeof(d));
    d[1]=0;
    q.push(make_pair(0,1));
    while(!q.empty())
    {
        k=q.top().vecin;
        q.pop();
        viz[k]=1;
        for(vector<pair<int,int> >::iterator ii=g[k].begin();ii!=g[k].end();++ii)
            if(!viz[ii->vecin]&&d[ii->vecin]>ii->cost)
            {
                d[ii->vecin]=ii->cost;
                q.push(make_pair(-d[ii->vecin],ii->vecin));
                t[ii->vecin]=k;
            }
    }
}

void afisare()
{
    int s=0;
    for(int i=1;i<=n;i++)
        s+=d[i];
    printf("%d\n%d\n",s,n-1);
    for(int i=2;i<=n;i++)
        printf("%d %d\n",i,t[i]);
}

int main()
{
    freopen("apm.in","r",stdin);
    freopen("apm.out","w",stdout);
    citire();
    prim();
    afisare();
    return 0;
}