Cod sursa(job #2154514)

Utilizator DenisPetreCsRekkles DenisPetre Data 6 martie 2018 23:45:55
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.54 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

const int NMax=50001;
const int oo=(1<<30);

int N,M;
int D[NMax];
bool inCoada[NMax];

vector < pair <int,int> > G[NMax];

struct compara
{
    bool operator()(int x, int y)
    {
        return D[x]>D[y];
    }
};

priority_queue<int, vector<int>, compara> Coada;

void citeste()
{
    fin>>N>>M;
    for(int i=1;i<=M;i++)
    {
        int x,y,c;
        fin>>x>>y>>c;
        G[x].push_back(make_pair(y,c));
    }
}
void afiseaza()
{
    for(int i=1;i<=N;i++)
    {
        if(D[i]!=oo)
            fout<<D[i]<<" ";
        else
            fout<<"0";
    }
}

void dijkstra(int nod_start)
{
    for(int i=1;i<=N;i++)
        D[i]=oo;
    D[nod_start]=0;

    Coada.push(nod_start);
    inCoada[nod_start]=true;

    while(!Coada.empty())
    {
        int nodCurent=Coada.top();
        Coada.pop();
        for(size_t i=1;i<G[nodCurent].size();i++)
        {
            int Vecin=G[nodCurent][i].first;
            int Cost=G[nodCurent][i].second;
            if(D[nodCurent]+Cost<D[Vecin])
            {
                D[Vecin] = D[nodCurent] + Cost;
                if(inCoada[Vecin] == false)
                {
                    Coada.push(Vecin);
                    inCoada[Vecin] = true;
                }
            }
        }
    }
}



int main()
{
    citeste();
    dijkstra(1);
    afiseaza();
    return 0;
}