Cod sursa(job #2968772)

Utilizator mihaistamatescuMihai Stamatescu mihaistamatescu Data 21 ianuarie 2023 22:32:05
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.46 kb
#include <fstream>
#include <vector>
#include <deque>
#include <bitset>

#define DIM 50010
#define INF 2000000000
using namespace std;
int n, m, x, y, z, D[DIM], cnt[DIM], verif;
vector<pair<int, int> > L[DIM];
deque<int> c;
bitset<DIM> viz;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");

void bellman_ford(int p) {
    c.push_back(p);
    viz[p] = true;
    while (!c.empty()) {
        int nod = c.front();
        c.pop_front();
        viz[nod] = false;
        for (int i = 0; i < L[nod].size(); i++) {
            int vecin = L[nod][i].first;
            int cost = L[nod][i].second;
            if (D[vecin] > D[nod] + cost) {
                D[vecin] = D[nod] + cost;
                if (viz[vecin] == 0) {
                    cnt[vecin]++;
                    if (cnt[vecin] >= n) {
                        fout << "Ciclu negativ!";
                        verif = 1;
                        return;
                    }
                    c.push_back(vecin);
                    viz[vecin] = 1;
                }
            }
        }
    }
}

void init(int *D, int x) {
    for (int i = 1; i <= n; i++) {
        D[i] = INF;
    }
    D[x] = 0;
}

int main() {
    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        fin >> x >> y >> z;
        L[x].push_back(make_pair(y, z));
    }
    init(D, 1);
    bellman_ford(1);
    if (verif == 1) {
        return 0;
    }
    for (int i = 2; i <= n; i++) {
        fout << D[i] << " ";
    }
    return 0;
}