Cod sursa(job #2039779)

Utilizator DavidLDavid Lauran DavidL Data 14 octombrie 2017 21:54:13
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.33 kb
#include <fstream>
#include <queue>
#define MAXN 50005
#define INF 100000000
using namespace std;
ifstream fi("bellmanford.in");
ofstream fo("bellmanford.out");

int n,m;
int dist[MAXN],viz[MAXN];
queue <int> Q;
vector < pair<int,int> > G[MAXN];
bool coada[MAXN];
int main()
{
    fi>>n>>m;
    for (int i=1; i<=m; i++)
    {
        int u,v,c;
        fi>>u>>v>>c;
        G[u].push_back(make_pair(v,c));
    }
    for (int i=2; i<=n; i++)
        dist[i]=INF;
    Q.push(1);
    coada[1]=1;
    while (!Q.empty())
    {
        int nod=Q.front();
        coada[nod]=0;
        Q.pop();
        for (auto copil: G[nod])
        {
            if (dist[nod]+copil.second<dist[copil.first])
            {
                if (viz[copil.first]>n)
                {
                    fo<<"Ciclu negativ!";
                    fi.close();
                    fo.close();
                    return 0;
                }
                dist[copil.first]=dist[nod]+copil.second;
                if (!coada[copil.first])
                {
                    Q.push(copil.first);
                    coada[copil.first]=1;
                    viz[copil.first]++;
                }
            }
        }
    }
    for (int i=2; i<=n; i++)
        fo<<dist[i]<<" ";
    fi.close();
    fo.close();
    return 0;
}