Cod sursa(job #1033546)

Utilizator ionicaion ionica Data 17 noiembrie 2013 10:05:31
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.65 kb
#include<fstream>
#include<vector>
#include<queue>
#include<functional>
#define NMAX 50001
#define INF 2500010
#define f first
#define s second
#include<stdio.h>

using namespace std;

//ifstream f("dijkstra.in");
FILE *f=fopen("dijkstra.in","r");
//ofstream g("dijkstra.out");
FILE *g=fopen("dijkstra.out","w");

int n, m, D[NMAX];

vector<pair<int, int> > a[NMAX];
priority_queue <pair<int, int>, vector<pair<int, int> >, greater<pair<int, int> > > H;

void Citeste()
{
    int i, x, y, c;

    //f>>n>>m;
    fscanf(f,"%d %d",&n,&m);

    for (i=1; i<=m; ++i)
    {
        //f>>x>>y>>c;
        fscanf(f,"%d %d %d",&x,&y,&c);
        a[x].push_back(make_pair(c, y));
    }
}
void Initializeaza()
{
    int i;

    for (i=2; i<=n; ++i) D[i]=INF;

    D[1]=0;

    H.push(make_pair(0, 1));
}

void Solve()
{
    pair<int, int> pr;
    vector<pair<int, int> > :: iterator it;
    int z;

    while (!H.empty())
    {
        pr=H.top(); H.pop();

        if (pr.f==D[pr.s])
        {
            for (it=a[pr.s].begin(); it!=a[pr.s].end(); ++it)
            {
                z=pr.f+it->f;
                if (D[it->s]>z)
                {
                    H.push(make_pair(z, it->s));
                    D[it->s]=z;
                }
            }
        }
    }
}

void Scrie()
{
    int i;

    for (i=2; i<=n; ++i)
        if (D[i]==INF) //g<<"0 ";
              fprintf(g,"%d ",0);
            else //g<<D[i]<<" ";
               fprintf(g,"%d ",D[i]);
}

int main()
{
    Citeste();

    Initializeaza();

    Solve();

    Scrie();

//    f.close();
//    g.close();
    return 0;
}