Bellman-Ford

#include <bits/stdc++.h>

using namespace std;

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

int N, M, x, y, c;
const int maxn = 50005;
const int INF = 0x3f3f3f3f;
vector < pair < int , int > > G[maxn];

int main () {
    fin >> N >> M;
    while (M --) {
        fin >> x >> y >> c;
        G[x].push_back ({y, c});
    }
    queue < int > Q;
    bitset < maxn > inQ (false);
    vector < int > dist (maxn, INF), cntinQ (maxn, 0);
    bool ciclu_negativ = false;
    dist[1] = 0, Q.push (1), inQ[1] = true;
    while (!Q.empty() && !ciclu_negativ) {
        int x = Q.front ();
        Q.pop ();
        inQ[x] = false;
        vector < pair < int , int > > :: iterator it;
        for (it = G[x].begin(); it != G[x].end(); ++it)
        if (dist[x] < INF)
        if (dist[it -> first] > dist[x] + it -> second) {
            dist[it -> first] = dist[x] + it -> second;
            if (!inQ[it -> first]) {
                if (cntinQ[it -> first] > N) ciclu_negativ = true;
                else {
                    Q.push (it -> first);
                    inQ[it -> first] = true;
                    cntinQ[it -> first] ++;
                }
            }
        }
    }
    if (!ciclu_negativ) for (int i = 2; i <= N; i ++) fout << dist[i] << ' ';
    else fout << "Ciclu negativ!\n";
    fin.close ();
    fout.close ();
    return 0;
}