Cod sursa(job #2203066)

Utilizator MaaaaaCristina Ma Maaaaa Data 10 mai 2018 20:22:58
Problema Algoritmul Bellman-Ford Scor 65
Compilator cpp Status done
Runda Arhiva educationala Marime 1.43 kb
#include <fstream>
#include <vector>
#define nmax 50005
#define mmax 250005
#define inf 2000000000
using namespace std;
fstream f1("bellmanford.in", ios::in);
fstream f2("bellmanford.out", ios::out);
int n, m, viz[nmax], coada[mmax], prim, ultim, k, dist[nmax], pred[nmax], iter[nmax], ok=1;
vector<pair<int, int> > v[nmax];
void citire()
{
    int i, x, y,c;
    f1>>n>>m;
    for(i=1; i<=m; i++)
    {
        f1>>x>>y>>c;
        v[x].push_back({y,c});
        ///v[y].push_back({x,c});
    }
}
void solutie()
{
    int i, nod, vec, ct;
    viz[1]=1;
    prim=ultim=k=1;
    coada[prim]=1;
    for(i=2; i<=n; i++)
        dist[i]=inf;
    while((k!=0)&&(ok))
    {
        nod=coada[prim]; viz[nod]=0; prim++; k--;

        for(auto it=v[nod].begin(); it!=v[nod].end(); ++it)
            if((dist[(*it).first]> dist[nod]+ (*it).second)&&(dist[nod]!=inf))
        {
            vec=(*it).first; ct=(*it).second;
            dist[vec]= dist[nod]+ct;
            pred[vec]=nod;
            if(!viz[vec])
            {
                k++; ultim++; coada[ultim]=vec;
                viz[vec]=1;
                iter[vec]++;
                if(iter[vec]> n) ok=0;
            }
        }
    }
}
void afis()
{
    int i;
    if(!ok) f2<<"Ciclu negativ!";
    else
    {
    for(i=2; i<=n; i++)
        f2<<dist[i]<<' ';
    }
}
int main()
{
    citire();
    solutie();
    afis();
    return 0;
}