Cod sursa(job #2856743)

Utilizator casian116Sandu Costin-Casian casian116 Data 24 februarie 2022 11:42:34
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.56 kb
#include <fstream>
#include <queue>
#include <vector>
#define NMAX 50007
#define INF 1e9
using namespace std;

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

struct varf
{
    int x;
    int cost;
};

vector<varf> G[NMAX]; ///lsite de adiacenta u costuri
queue<int> C;

bool uz[NMAX];
bool bf();
int n, x0 = 1, x, vf, cost1, m, rez;
int cmin[NMAX], pre[NMAX];
int nr[NMAX];///nr[i] = nr drumuri de cost minim de la x la i
void afisare();
void citire();

int main()
{
    citire();
    rez = bf();
    afisare();
    return 0;
}
void citire()
{
    int i,j,c;
    varf aux;
    nr[x0] = 1;
    fin>>n>>m;
    while(fin>>i>>j>>c)
    {
        ///in lista de adiacenta a lui i trebuie sa adaug (j,c)
        aux.x=j;
        aux.cost=c;
        G[i].push_back(aux);
    }
    for(i=1; i<=n; i++) cmin[i]=INF;
    cmin[x0]=0;
}
bool bf()
{
    ///initializez coada cu vrarful de start
    C.push(x0);
    nr[0] = 1;
    while(!C.empty())
    {
        x = C.front();
        C.pop();
        for (int i = 0; i < G[x].size(); i++)
        {
            vf = G[x][i].x;
            cost1 = G[x][i].cost;
            if (cmin[vf] > cmin[x]+cost1)
            {
                cmin[vf] = cmin[x]+cost1;
                C.push(vf);
                nr[vf]++;
                if (nr[vf] == n) return 0;///exista circuite de cost negativ
            }
        }
    }
    return 1;
}
void afisare()
{
    if (rez == 0) fout << "Ciclu negativ!";
    else for (int i = 2; i <= n; i++) fout << cmin[i] << ' ';
}