Cod sursa(job #2138487)

Utilizator borzaalexAlexandru Borza borzaalex Data 21 februarie 2018 18:00:57
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.59 kb
#include    <iostream>
#include    <fstream>
#include    <queue>
#include    <vector>

using namespace std;

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

const int NMax = 50005;
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 Dijkstra(int nodStart)
{
   for(int i=1;i<=N;i++)
        D[i]=oo;
   D[nodStart]=0;
   InCoada[nodStart]=true;
   Coada.push(nodStart);
   while(!Coada.empty())
   {
        int nodCurent=Coada.top();
        Coada.pop();
        InCoada[nodCurent]=false;
        for(size_t i=0;i<G[nodCurent].size();i++)
        {
            int Vecin=G[nodCurent][i].first;
            int Cost=G[nodCurent][i].second;
            if(D[Vecin]>D[nodCurent]+Cost)
            {
                D[Vecin]=D[nodCurent]+Cost;
                if(InCoada[Vecin]==false)
                {
                    InCoada[Vecin]=true;
                    Coada.push(Vecin);
                }
            }
        }
   }
}

void Afiseaza()
{
    for(int i = 2; i <= N; i++)
    {
        if(D[i] != oo)
            fout << D[i] << " ";
        else
            fout << "0 ";
    }
}

int main()
{
    Citeste();
    Dijkstra(1);
    Afiseaza();
}