Cod sursa(job #968147)

Utilizator Andrei1998Andrei Constantinescu Andrei1998 Data 1 iulie 2013 20:38:18
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.61 kb
#include <fstream>
#include <bitset>
#include <list>
#include <queue>

using namespace std;

#define inf 250000005

int d[50005];
bitset<50005> viz;

struct elem
{
    int ind;
    int val;
};

struct nod
{
    list<elem> vecini;
}graf[50005];

bool operator<(const elem &a,const elem &b)
{
    if(a.val<b.val)
        return 1;
    return 0;
}

int main()
{
    ifstream fin("dijkstra.in");
    ofstream fout("dijkstra.out");
    priority_queue<elem> coada;
    int n,m,a,b,c,i;
    elem aux;
    fin>>n>>m;

    for(i=0;i<m;i++)
    {
        fin>>a>>b>>c;
        a--;
        b--;
        aux.ind=b;
        aux.val=c;
        graf[a].vecini.push_back(aux);
    }
    for(i=1;i<n;i++)
        d[i]=inf;
    aux.ind=0;
    aux.val=0;
    coada.push(aux);
    //viz[0]=1; - fals (daca fac asa, atunci nici macar nu incepe algoritmul)
    list<elem>::iterator it;
    elem aux2;
    while(!coada.empty())
    {
        aux=coada.top();
        //cout<<"extragem "<<aux.ind<<endl;
        coada.pop();
        if(!viz[aux.ind])
        {
            viz[aux.ind]=1;
            for(it=graf[aux.ind].vecini.begin();it!=graf[aux.ind].vecini.end();it++)
            {
                if(aux.val+(*it).val<d[(*it).ind])
                {
                   d[(*it).ind]=aux.val+(*it).val;
                   aux2.ind=(*it).ind;
                   aux2.val=d[(*it).ind];
                   coada.push(aux2);
                }
            }
        }
    }
    for(i=1;i<n;i++)
        fout<<d[i]<<' ';
    fout<<'\n';
    fin.close();
    fout.close();
    return 0;
}