Cod sursa(job #3296347)

Utilizator emcerchezEmanuela Cerchez emcerchez Data 12 mai 2025 12:11:50
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.41 kb
//Nemtisor Andrei
#include <fstream>
#include <vector>
#include <queue>
#define NMAX 50001
#define INF 1000000002

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


int n;
int cmin[NMAX];
vector <pair<int,int>> G[NMAX];
priority_queue <pair <int, int>, vector <pair <int, int>>, greater <pair <int, int>>> h;
bool viz[NMAX];
//G[x] lista de adiacenta cu costuri a varfului x
//in pair primul camp este varful
//al doilea este costul

void citire();
void dijkstra(int);

int main()
{
 citire();
 dijkstra(1);
 for(int i=2; i<=n; ++i)
    fout<<(cmin[i] == INF ? 0 : cmin[i])<<' ';
 return 0;
}

void citire()
{
    int k,m,x,y,c;
 fin>>n>>m;
 for (k=0; k<m; k++)
     {
      fin>>x>>y>>c;
      G[x].push_back({y, c});
     }
}

void dijkstra(int source)
{
    int vfmin, i, mini, x, c;
    for(i=1; i<=n; ++i)
        cmin[i] = INF;
    cmin[source] = 0;
    viz[source] = 1;
    h.push( { 0, source } );
    while(!h.empty())
    {
        c = h.top().first;
        x = h.top().second;
        h.pop();
        if( viz[x] ){
            continue;
        }
        viz[x] = 1;
        for( i = 0; i < G[x].size(); i++ ){
            if( cmin[G[x][i].first] > c + G[x][i].second ){
                h.push( { c + G[x][i].second, G[x][i].first } );
                cmin[G[x][i].first] = c + G[x][i].second;
            }
        }
    }
}