Cod sursa(job #2784867)

Utilizator TudosieRazvanTudosie Marius-Razvan TudosieRazvan Data 17 octombrie 2021 16:32:01
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.46 kb
#include <fstream>
#include <queue>
#include <climits>

using namespace std;

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

int n,m;

struct element{
    int nod,cost;
};

bool eViz[50001];
int cicluri[50001];
int d[50001],ok;
vector<element> graf[50001];
queue<int>coada;

void bfs(int start)
{
    for(int i=1; i<=n; i++)
    {
        d[i]=INT_MAX;
    }

    coada.push(start);
    d[start]=0;
    eViz[start]=true;
    while(!coada.empty())
    {
        int prec=coada.front();
        eViz[prec]=false;
        coada.pop();
        cicluri[prec]++;
        if(cicluri[prec]>=n)
        {
            fout<<"Ciclu negativ!";
            ok=1;
            return;
        }
        for(int i=0; i<graf[prec].size(); i++)
        {
            int fiu=graf[prec][i].nod;
            int cost=graf[prec][i].cost;
            if(d[fiu]>d[prec]+cost)
            {
                d[fiu]=d[prec]+cost;
                //adaug in coada
                if(eViz[fiu]==0)
                {
                  coada.push(fiu);
                  eViz[fiu]=1;
                }
            }
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y,cost;
        fin>>x>>y>>cost;
        graf[x].push_back({y,cost});
    }
    bfs(1);
    if(ok==0)
    {
       for(int i=2; i<=n; i++)
       {
           fout<<d[i]<<" ";
       }

    }


    return 0;
}