Cod sursa(job #968328)

Utilizator Andrei1998Andrei Constantinescu Andrei1998 Data 1 iulie 2013 22:41:28
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.62 kb
#include <fstream>
#include <bitset>
#include <list>
#include <queue>

using namespace std;

#define inf 0x3f3f3f3f

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

struct elem
{
    int ind;
    int val;
};

list<elem> 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;
        aux.ind=b;
        aux.val=c;
        graf[a].push_back(aux);
    }
    for(i=2;i<=n;i++)
        d[i]=inf;
    aux.ind=1;
    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();
        //fout<<"se extrage "<<aux.ind<<' '<<aux.val<<endl;
        coada.pop();
        if(!viz[aux.ind])
        {
            viz[aux.ind]=1;
            for(it=graf[aux.ind].begin();it!=(graf[aux.ind].end());it++)
            {
                if((aux.val+(it->val))<d[it->ind])
                {
                   d[it->ind]=aux.val+(it->val); //jumate
                   aux2.ind=it->ind;
                   aux2.val=d[it->ind];
                   coada.push(aux2);
                }
            }
        }
    }
    for(i=2;i<=n;i++)
        if(d[i]==inf)
           fout<<"0 ";
        else
        fout<<d[i]<<' ';
    fout<<'\n';
    fin.close();
    fout.close();
    return 0;
}