Cod sursa(job #2359786)

Utilizator grecubogdanGrecu Bogdan grecubogdan Data 1 martie 2019 09:30:55
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
const int oo=(1<<30);
queue<int> q;
vector<pair<int,int> >G[50005];
int n,i,j,x,y,z,m,viz[50005],inq[50005],d[50005];
int bf(int nod)
{
    int i,vecin,cost,nc;
    for(i=1;i<=n;i++)
    {
        viz[i]=0;
        inq[i]=0;
        d[i]=oo;
    }
    d[nod]=0;
    q.push(nod);
    inq[nod]=1;
    while(!q.empty())
    {
        nc=q.front();
        viz[nc]++;
        if(viz[nc]>=n) return 0;
        q.pop();
        inq[nc]=0;
        for(i=0;i<G[nc].size();i++)
        {
            vecin=G[nc][i].first;
            cost=G[nc][i].second;
            if(d[nc]+cost<d[vecin])
            {
                d[vecin]=d[nc]+cost;
                if(!inq[vecin])
                    q.push(vecin);
            }
        }
    }
    return 1;
}
int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y>>z;
        G[x].push_back(make_pair(y,z));
    }
    if(bf(1))
    {
        for(i=2;i<=n;i++)
            g<<d[i]<<" ";
    }
    else
        g<<"Ciclu negativ!";
    return 0;
}