Cod sursa(job #2198964)

Utilizator Anastasia11Susciuc Anastasia Anastasia11 Data 25 aprilie 2018 23:07:23
Problema Algoritmul Bellman-Ford Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
#include <cstring>
#include <vector>
#include <queue>
#define Nmax 50005
#define INF 1000000005

using namespace std;

ifstream f("bellmanford.in");
ofstream g("bellmanford.out");

vector <int> ls[Nmax], lc[Nmax];
int n, m, x, y, cost;
queue <int> Q;
int seen[Nmax], cnt[Nmax];

int main() {
    f >> n >> m;
    while ( m -- )
    {
        f >> x >> y >> cost;
        ls[x].push_back(y);
        lc[x].push_back(cost);
    }
    memset(seen, INF, Nmax);
     seen[1]=0;
     Q.push(1);
    while (Q.empty()==0) {
        int old_n = Q.front();
        Q.pop();
        int l = ls[old_n].size();
        for ( int i = 0 ; i < l ; i ++ )
         {
            int new_n = ls[old_n][i];
            int new_c = lc[old_n][i];
            if (seen[old_n]+new_c < seen[new_n])
            {
                seen[new_n] = seen[old_n]+new_c;
                cnt[new_n]++;
                Q.push(new_n);
            }
            if (cnt[new_n] >= n)
             {
                g << "Ciclu negativ!";
                return 0;
            }
        }
    }
    for ( int i = 2 ; i <= n ; i ++ )
        g << seen[i] << ' ';
    return 0;
}