Cod sursa(job #1269357)

Utilizator gabrielinelusGabriel-Robert Inelus gabrielinelus Data 22 noiembrie 2014 10:04:58
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>
#include <queue>

#define Nmax 200005
#define INF 0x3f3f3f3f
using namespace std;

vector<pair<int,int> > G[Nmax];
priority_queue<pair<int,int> > Q;
int daddy[Nmax],DP[Nmax],used[Nmax];
int N,M;

void read()
{
    scanf("%d%d",&N,&M);
    int a,b,c;
    for(int i = 1; i <= M; ++i)
    {
        scanf("%d%d%d",&a,&b,&c);
        G[a].push_back(make_pair(c,b));
        G[b].push_back(make_pair(c,a));
    }
}

void prim(int k)
{
    memset(DP,INF,sizeof(DP));
    DP[k] = 0;
    Q.push(make_pair(0,k));
    while(!Q.empty())
    {
        k = Q.top().second;
        used[k] = 1; Q.pop();
        for(vector<pair<int,int> >::iterator it = G[k].begin(); it != G[k].end();++it)
            if(!used[it->second] && DP[it->second] > it->first)
            {
                daddy[it->second] = k;
                DP[it->second] = it->first;
                Q.push(make_pair(-DP[it->second],it->second));
            }
    }
}

void print()
{
    int cost = 0;
    for(int i = 2; i <= N; ++i)
        cost += DP[i];
    printf("%d\n%d\n",cost,N-1);
    for(int i = 2; i <= N; ++i)
        printf("%d %d\n",i,daddy[i]);
}
int main()
{
    freopen("apm.in","r",stdin);
    freopen("apm.out","w",stdout);

    read();
    prim(1);
    print();

    return 0;
}