Cod sursa(job #2374145)

Utilizator BurlacuMateiBurlacu Matei BurlacuMatei Data 7 martie 2019 17:11:06
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.58 kb
#include <fstream>
#include <vector>
#include <queue>
#define MAX 50100
#define INF 1000000000

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

struct arc
{
    int nod, cost;
};

vector <arc> G[MAX];
priority_queue <arc> pq;

int n, m;
int x, y, c;
int cmin[MAX];
bool uz[MAX];

void citire();
void dijkstra();
void afisare();

inline bool operator<(arc x, arc y)
{
    return x.nod > y.nod;
}

int main()
{
    citire();
    dijkstra();
    afisare();
    return 0;
}

void citire()
{
    int i;
    arc aux;

    fin >> n >> m;
    for(i=1; i<=m; i++)
    {
        fin >> x >> y >> c;

        aux.nod = y;
        aux.cost = c;
        G[x].push_back(aux);
    }
}

void dijkstra()
{
    arc vecin, varf;
    int i, cost, nod;
    for(i=1; i<=n; i++)
        cmin[i] = INF;

    cmin[1] = 0;
    uz[1] = true;

    pq.push({1, 0});

    while(!pq.empty())
    {
        varf = pq.top();
        pq.pop();

        nod = varf.nod;
        cost = varf.cost;

        uz[nod] = true;

        for(i=0; i<G[nod].size(); i++)
            if(!uz[G[nod][i].nod])
            {
                vecin = G[nod][i];

                if(cost + vecin.cost < cmin[vecin.nod])
                {
                    cmin[vecin.nod] = cost + vecin.cost;
                    pq.push({vecin.nod, cost + vecin.cost});
                }
            }
    }
}

void afisare()
{
    int i;

    for(i=2; i<=n; i++)
        if(cmin[i] < INF) fout << cmin[i] << ' ';
        else fout << 0 << ' ';
}