Cod sursa(job #2819354)

Utilizator andreitabaraandrei2004 andreitabara Data 18 decembrie 2021 11:34:05
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.3 kb
#include <fstream>
#define inf 1000000000
#include <queue>
#include <vector>
#define f first
#define s second
#include <cstdlib>
using namespace std;
ifstream in ("bellmanford.in");
ofstream out ("bellmanford.out");
priority_queue<pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > h;
vector<pair<int,int> >v[50001];
int n,m,ok,a,b,c,d[500001],viz[500001];
void bellmanford()
{
    for(int i=1;i<=n;i++)
    {
        d[i]=inf;
    }
    d[1]=0;
    h.push({0,1});
    while(!h.empty()&&ok==0)
    {
        int nod=h.top().s;
        h.pop();
        for(int i=0;i<v[nod].size();i++)
        {
            if(d[v[nod][i].s]>d[nod]+v[nod][i].f)
            {
                viz[v[nod][i].s]++;
                d[v[nod][i].s]=d[nod]+v[nod][i].f;
                h.push({d[v[nod][i].s],v[nod][i].s});
                if(viz[v[nod][i].s]==n)
                {
                    out<<"Ciclu negativ!"<<'\n';
                    ok=1;
                  exit(0);
                }
            }
        }
    }
}
int main()
{
    in>>n>>m;
    for(int i=1;i<=m;i++)
    {
        in>>a>>b>>c;
        v[a].push_back({c,b});
    }
    bellmanford();
    if(ok==0)
       {
            for(int i=2;i<=n;i++)
            out<<d[i]<<" ";
       }
    return 0;
}