Cod sursa(job #2011180)

Utilizator dragomirmanuelDragomir Manuel dragomirmanuel Data 15 august 2017 14:53:21
Problema Arbore partial de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.55 kb
#include <iostream>
#include <cstdio>
#include <queue>
#include <vector>
#include <cstring>
#include <bitset>

#define mp make_pair
#define pb push_back

using namespace std;

const int NodMax = 200005;
const int MuchMax = 400005;

int N, M, dist[NodMax], tata[NodMax];
priority_queue < pair < int, int > > Q; //cost si vecin
vector < pair < int, int > > G[MuchMax]; // cost si vecin
bitset < NodMax > viz;

void Read()
{
    scanf("%d %d", &N, &M);
    for(int i=1; i<=M; ++i)
    {
        int x, y, c;
        scanf("%d %d %d", &x, &y, &c);
        G[x].pb(mp(c,y));
        G[y].pb(mp(c,x));
    }
}

void Solve()
{
    int inf = 0x3f3f3f3f;
    Q.push(mp(0,1));
    memset(dist,inf,sizeof(dist));

    while(!Q.empty())
    {
        int nodc = Q.top().second;
        Q.pop();

        viz[nodc] = true;

        vector < pair < int, int > > ::iterator it;

        for(it = G[nodc].begin(); it!=G[nodc].end(); ++it)
        {
            if(dist[it->second] > it->first && !viz[it->second])
            {
                dist[it->second] = it->first;
                Q.push(mp(-dist[it->second],it->second));
                tata[it->second] = nodc;
            }
        }

    }
    int S = 0;

    for(int i = 2; i <= N; ++i)
            S += dist[i];

    cout << S << "\n" << N-1 << "\n";

    for(int i = 2; i <= N; ++i)
        cout << i << " " << tata[i] << "\n";
}

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