Cod sursa(job #2681281)

Utilizator darisavuSavu Daria darisavu Data 5 decembrie 2020 11:10:29
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.2 kb
#include <bits/stdc++.h>
#define inf 1e9
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int n,m,i,j,x,y,c;
int d[50005],viz[50005];
vector<pair< int,int> >v[50005];
priority_queue< pair<int,int>, vector< pair<int,int> >, greater<pair<int,int> > >q;
void bellmanford(int x)
{
    int nod;
    q.push({0,x});
    d[x]=0;
    while(!q.empty())
    {
        nod=q.top().second;
        q.pop();
        for(int i=0; i<v[nod].size(); i++)
        {
            if(d[nod]+v[nod][i].first<d[v[nod][i].second])
            {
                viz[v[nod][i].second]++;
                d[v[nod][i].second]=d[nod]+v[nod][i].first;
                q.push({d[v[nod][i].second],v[nod][i].second});
                if(viz[v[nod][i].second]==n)
                {
                    g<<"Ciclu negativ!";
                    exit(0);
                }
            }
        }




    }
}
int main()
{
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>x>>y>>c;
        v[x].push_back({c,y});
    }
    for(i=1; i<=n; i++)  d[i]=inf;
    bellmanford(1);
    for(i=2; i<=n; i++)
    {
        if(d[i]==inf) d[i]=0;
        g<<d[i]<<" ";
    }
    return 0;
}