Cod sursa(job #2676700)

Utilizator Snake2003lalallalal Snake2003 Data 24 noiembrie 2020 19:35:22
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.77 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

#define pi pair < int, int >
#define Nmax 50005

using namespace std;

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

int vf, muchii, x, y, cost;
int Distanta[Nmax], NrQ[Nmax];

vector < pi > Numbers[Nmax];
priority_queue < int, vector < int >, greater < int > > Coada;

bool ok = false;
bool Visited[Nmax];

int Dijkstra( int Nod_S )
{
    int Nod, Vecin, Cost, C;

    for( int i =1; i <= vf; ++ i )
        Distanta[i] = 1e9;
    Distanta[Nod_S] = 0;

    Coada.push(Nod_S);
    Visited[Nod_S] = true;

    while( !Coada.empty() )
    {
        Nod = Coada.top();
        Coada.pop();

        Visited[Nod] = false;
        for( unsigned int i = 0; i < Numbers[Nod].size() && !ok; ++ i )
        {
            Vecin = Numbers[Nod][i].first;
            Cost = Numbers[Nod][i].second;

            if( Distanta[Nod] + Cost < Distanta[Vecin] )
            {
                Distanta[Vecin] = Distanta[Nod] + Cost;
                if( !Visited[Vecin])
                {
                    if( NrQ[Vecin] < vf )
                    {
                        Visited[Vecin] = true;
                        Coada.push(Vecin);
                        NrQ[Vecin] ++;
                    }
                    else
                        ok = true;
                }
            }
        }
    }
    return ok;
}

int main()
{
    fin >> vf >> muchii;
    for( int i = 1; i <= muchii; ++ i )
    {
        fin >> x >> y >> cost;
        Numbers[x].push_back({y, cost});
    }
    if(Dijkstra(1) == false)
        for( int i = 2; i <= vf; ++ i )
            fout << Distanta[i] << " ";
    else
        fout << "Ciclu negativ!";
    return 0;
}