Cod sursa(job #2163806)

Utilizator marcdariaDaria Marc marcdaria Data 12 martie 2018 20:03:06
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");

using PII = pair<int,int>;
vector <PII> G[50001];
int d[50001],p[50001],nr[50001];
int n,m;
const int Inf=0x3f3f3f3f;
bool v[50001];

int main()
{
    fin>>n>>m;
    while(m--)
    {
        int x,y,cost;
        fin>>x>>y>>cost;
        G[x].push_back({y,cost});
    }

    for(int i=0;i<=n;++i)
    {
        d[i]=Inf; p[i]=0; v[i]=false;
    }

    v[1]=true;
    d[1]=0;

    queue <int> Q;
    Q.push(1);

    while(!Q.empty())
    {
        int nod=Q.front();
        v[nod]=false;
        vector <PII>::iterator it;
        for(it=G[nod].begin();it!=G[nod].end();++it)
            if(d[nod]+it->second<d[it->first])
        {
            d[it->first]=d[nod]+it->second;
            if(!v[it->first])
            {
                if(nr[it->first]>n)
                {
                    fout<<"Ciclu negativ!\n";
                    return 0;
                }

                Q.push(it->first);
                v[it->first]=true;
                ++nr[it->first];
            }
        }

        Q.pop();
    }

    for(int i=2;i<=n;++i)
        fout<<d[i]<<" ";

    return 0;
}