Cod sursa(job #2552935)

Utilizator Robys01Robert Sorete Robys01 Data 21 februarie 2020 12:53:40
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <bits/stdc++.h>
#define NMAX 50001
#define INF (1<<30)
using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

int n, m, dist[NMAX];
vector < pair <int, int> > A[NMAX];
priority_queue < pair <int, int> >Q;
bitset <NMAX> viz;


void citire()
{
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x, y, c; fin>>x>>y>>c;
        A[x].push_back( {y, c} );
        A[y].push_back( {x, c} );
    }
    for(int i=2; i<=n; i++)
        dist[i] = INF;

}

void dijkstra()
{
    Q.push( {0, 1});
    while(!Q.empty())
    {
        while(!Q.empty() && viz[Q.top().second] == 1)
            Q.pop();
        if(Q.empty())
            break;
        int K = Q.top().second;
        Q.pop();

        viz[K] = 1;
        for(auto a : A[K])
        {
            int vecin = a.first; int cost = a.second;

            if(dist[vecin] > dist[K] + cost)
            {
                dist[vecin] = dist[K] + cost;
                Q.push( {-dist[vecin], vecin} );
            }

        }
    }
    for(int i=1; i<=n; i++)
        fout<< (dist[i] != INF ? dist[i] : -1)<<' ';

}

int main()
{
    citire();
    dijkstra();

    return 0;
}