Cod sursa(job #2723306)

Utilizator maria.rotaruMaria Rotaru maria.rotaru Data 13 martie 2021 21:19:54
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.38 kb
#include <fstream>
#include <vector>
#define NMAX 50000

using namespace std;

ifstream cin("bellmanford.in");
ofstream cout("bellmanford.out");

int n,m, coada[NMAX+5];
int esteincoada[NMAX+5],viz[NMAX+5], d[NMAX+5];

vector < pair <int, int>> v[NMAX+1];
const int INF = 1000000000;

bool alg()
{
    for (int i=1; i<=n; i++)
    {
         d[i]=INF;
         viz[i]=0;
         esteincoada[i]=0;
    }

    d[1]=0;
    esteincoada[1]=1;
    int inc=1;
    int sf=1;
    coada[inc]=1;
    while (inc<=sf)
    {
        int nod = coada[inc];
        viz[nod]++;
        if (viz[nod] >=n )
            return false;
        coada[inc] = 0;
        esteincoada[nod] = 0;
        for (int i=0; i<v[nod].size(); i++)
        {

            int vecin = v[nod][i].first;
            int dist = v[nod][i].second;
            if (d[nod] + dist < d[vecin])
            {
                d[vecin] = d[nod] + dist;
                if (!esteincoada[vecin])
                    coada[++sf]=vecin;
            }
        }

        inc++;
    }
    return true;
}

int main()
{
    cin>>n>>m;
    for (int i=1; i<=m; i++)
    {
        int n1,n2,c;
        cin>>n1>>n2>>c;
        v[n1].push_back(make_pair(n2,c));
    }

    if (alg())
        for (int i=2; i<=n; i++)
            cout<<d[i]<<" ";
    else
        cout<<"Ciclu negativ!";

    return 0;
}