Cod sursa(job #2401137)

Utilizator andra_racovitaRacovita Andra-Georgiana andra_racovita Data 9 aprilie 2019 13:53:46
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.44 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

priority_queue <int, vector <int> > myheap;
int D[500003],N,M;
int viz[500003];
#define INF 2147483647
vector < pair <int,int> > G[500003];

void Citire()
{
    fin>>N>>M;
    int i;
    for(i=1;i<=M;i++)
    {
        int x,y,cost;
        fin>>x>>y>>cost;
        G[x].push_back(make_pair(y,cost));
    }
}

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

    for(i=1;i<=N;i++)
        viz[i]=0;
    myheap.push(nod_start);
    viz[nod_start]=1;

    while(!myheap.empty())
    {
        int nod=myheap.top();
        myheap.pop();
        viz[nod]=0;
        for(int i=0;i<G[nod].size();i++)
        {
            int Vecin=G[nod][i].first;
            int Cost=G[nod][i].second;
            if(D[nod]+Cost<D[Vecin])
            {
                D[Vecin]=D[nod]+Cost;
                if(viz[Vecin]==0)
                {
                    myheap.push(Vecin);
                    viz[Vecin]=1;
                }
            }
        }

    }
}

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

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