Cod sursa(job #2681298)

Utilizator DanAndrei1Cojocaru Dan Andrei DanAndrei1 Data 5 decembrie 2020 11:25:06
Problema Algoritmul lui Dijkstra Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>
using namespace std;
ifstream in ("dijkstra.in");
ofstream out ("dijkstra.out");

struct graf
{ int nod, cost; graf *next; };

int n, m;
graf *a[50001];
int d[50001], q[50001];

void add (int where, int what, int cost)
{
    graf *q = new graf;
    q->nod = what;
    q->cost = cost;
    q->next = a[where];
    a[where] = q;
}

void citire()
{
    in>>n>>m;

    int x, y, z;
    for ( int i = 1; i <= m; ++i )
    {
        in>>x>>y>>z;
        add(x, y, z);
    }
}

void dijkstra()
{
    for ( int i = 2; i <= n; ++i )
        d[i] = 1<<30;

    int min, pmin = 0;
    for ( int i = 1; i <= n; ++i )
    {
        min = 1<<30;

        for ( int j = 1; j <= n; ++j )
            if ( d[j] < min && !q[j] )
                min = d[j], pmin = j;

        q[pmin] = 1;

        graf *t = a[pmin];

        while ( t )
        {
            if ( d[ t->nod ] > d[pmin] + t->cost )
                d[ t->nod ] = d[pmin] + t->cost;

            t = t->next;
        }
    }
}

int main()
{
    citire();
    dijkstra();

    for ( int i = 2; i <= n; ++i )
        out<<(d[i] == 1<<30 ? 0 : d[i])<<' ';

	return 0;
}