Cod sursa(job #1073997)

Utilizator erickMarius Popovici erick Data 6 ianuarie 2014 23:44:39
Problema Algoritmul lui Dijkstra Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 2.19 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;
int V[NMAX], D[NMAX], T[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,j,minn,nod,ok,dist;
    for(i=1;i<=n;i++)
    {
        V[i]=0;
        D[i]=inf;
        T[i]=ns;
    }
    nou=cap[ns];
    while(nou)
    {
        D[nou->v]=nou->c;
        nou=nou->urm;
    }
    V[ns]=1;
    D[ns]=0;
    T[ns]=0;
    ok=1;
    while(ok)
    {
        minn=inf;
        for(i=1;i<=n;i++)
            if(V[i]==0)
                if(D[i]<minn)
                {
                    minn=D[i];
                    nod=i;
                }
        if(minn!=inf)
        {
            V[nod]=1;
            for(i=1;i<=n;i++)
                if(V[i]==0)
                {
                    dist=distanta(nod,i);
                    if(D[i]>D[nod]+dist)
                    {
                        D[i]=D[nod]+dist;
                        T[i]=nod;
                    }
                }
        }
        else ok=0;
    }
}

/*
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;
}