Cod sursa(job #2271958)

Utilizator mihailrazMihail Turcan mihailraz Data 29 octombrie 2018 15:31:25
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.35 kb
#include <fstream>
#include <vector>
#define NMAX 50000
#define INF 2000000000

using namespace std;
ifstream fi("bellmanford.in");
ofstream fo("bellmanford.out");
bool cicNeg=false;
int n, m;
int DST[NMAX+5];
vector <pair <int, int> > G[NMAX+5];

void citire(void)
{
    int x, y, c;
    fi>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fi>>x>>y>>c;
        G[x].push_back({c, y});
    }
}

void bellmanFord(void)
{
    int nods, cost;
    for(int i=1; i<=n; i++)
        DST[i]=INF;
    DST[1]=0;

    for(int i=1; i<=n-1; i++)
        for(int nod=1; nod<=n; nod++)
            for(auto vec:G[nod])
            {
                nods=vec.second;
                cost=vec.first;
                if(DST[nods]>DST[nod]+cost)
                    DST[nods]=DST[nod]+cost;
            }

    for(int nod=1; nod<=n && !cicNeg; nod++)
        for(auto vec:G[nod])
        {
            nods=vec.second;
            cost=vec.first;
            if(DST[nods]>DST[nod]+cost)
            {
                cicNeg=true;
                break;
            }
        }
}

void afisare(void)
{
    if(cicNeg)
        fo<<"Ciclu negativ!";
    else
        for(int i=2; i<=n; i++)
            fo<<DST[i]<<" ";
}

int main()
{
    citire();
    bellmanFord();
    afisare();
    fi.close();
    fo.close();
    return 0;
}