Cod sursa(job #1090418)

Utilizator bia423Bianca Floriana bia423 Data 22 ianuarie 2014 18:05:41
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.9 kb
#include <iostream>
#include <fstream>
using namespace std;
ifstream in ("dijkstra.in");
ofstream out("dijkstra.out");
const int inf = 1<<30;
const int NMAX = 50001;
const int max_arce=250001;
int coada[max_arce], D[NMAX];
int n,m;
struct lista
{
    int v;
    int c;
    lista *urm;
};
lista *cap[NMAX], *nou;

int distanta(int nod, int i)
{
    nou=cap[nod];
    while(nou)
    {
        if(nou->v==i) return nou->c;
        nou=nou->urm;
    }
    return inf;
}

void dijkstra(int ns)
{
    int i,pi,ps,nod,v,c;
    for(i=1;i<=n;i++)
        D[i]=inf;
    D[ns]=0;
    coada[1]=ns;
    pi=1;
    ps=1;
    while(pi<=ps)
    {
        nod=coada[pi];
        nou=cap[nod];
        while(nou)
        {
            v=nou->v; // vecinii celui de la inceputul cozii
            c=nou->c; //costurile legarii vecinilor la primul
            if(D[v]>D[nod]+c)
            {
                D[v]=D[nod]+c;
                ps++;
                coada[ps]=v;
            }
            nou=nou->urm;
        }cap[nod]=NULL;
        pi++;
    }
}

/*
void drum(int x)
{
    if (T[x])
    {
        drum(T[x]);
        out<<" "<<x;
    }
    else out<<x;
}
*/
int main()
{
    int i,a,b,c;
    in>>n>>m;
    for(i=1;i<=n;i++)
        cap[i]=NULL;
    for(i=1;i<=m;i++)
    {
        in>>a>>b>>c;
        nou=new lista;
        nou->v=b;
        nou->c=c;
        nou->urm=cap[a];
        cap[a]=nou;
    }
    in.close();
    /*
    for(i=1;i<=n;i++)
    {
        nou=cap[i];
        while(nou!=NULL)
        {
            out<<nou->v<<" ";
            nou=nou->urm;
        }
        out<<"\n";
    }
    */
    dijkstra(1);
    for(i=2;i<=n;i++)
        if(D[i]!=inf) out<<D[i]<<" ";
        else out<<0<<" ";
    /*
    out<<"\n";
    for(i=1;i<=n;i++)
        out<<T[i]<<" ";
    out<<"Drumul pana la 2 ";
    drum(2);
    */
    return 0;
}