Cod sursa(job #1570051)

Utilizator doruliqueDoru MODRISAN dorulique Data 16 ianuarie 2016 10:25:45
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.3 kb
/**
 Alg. lui Dijkstra
*/
#include <cstdio>
#include <vector>
#include <climits>
#define inf INT_MAX/2
using namespace std;

vector <pair<int,int> > lv[50001];
int viz[50001],t[50001],d[50001];

int main()
{
    int n,m,st,i,x,y,cost,j,k,dmin;
    FILE *f=fopen("dijkstra.in","r");
    fscanf(f,"%d%d",&n,&m);
    st=1;
    for(i=1;i<=n;i++)
    {
        t[i]=-1;
        d[i]=inf;
    }
    for(i=1;i<=m;i++)
    {
        fscanf(f,"%d%d%d",&x,&y,&cost);
        lv[x].push_back(make_pair(y,cost));
    }
    viz[st]=1;t[st]=0;
    vector <pair<int,int> >::iterator ii;
    for(ii=lv[st].begin();ii!=lv[st].end();++ii)
    {
        d[ii->first]=ii->second;
        t[ii->first]=st;
    }
    d[st]=0;
    for(i=1;i<=n-2;i++)
    {
        //determinam k=nodul nevizitat pt. kre d[k] minim
        dmin=inf;
        k=-1;
        for(j=1;j<=n;j++)
            if(!viz[j]&&d[j]<dmin)
                    dmin=d[k=j];
        if(k==-1)break;
        viz[k]=1;
        for(ii=lv[k].begin();ii!=lv[k].end();++ii)
            if(d[k]+ii->second<d[ii->first])
            {
                d[ii->first]=d[k]+ii->second;
                t[ii->first]=k;
            }
    }
    f=fopen("dijkstra.out","w");
    for(i=2;i<=n;i++)
        fprintf(f,"%d ",d[i]);
    return 0;
}