Cod sursa(job #2696860)

Utilizator dariahazaparuHazaparu Daria dariahazaparu Data 16 ianuarie 2021 23:43:51
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.32 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

const int N_MAX = 100005;
const int INF = 1e9;

std :: vector<std :: pair <int, int> > graph[N_MAX];
std :: queue <int> q;
int dist[N_MAX], cicle[N_MAX];
bool vis[N_MAX];
int n, m;


int main() {
    std::ifstream fin("bellamnford.in");
    std::ofstream fout("bellmanford.out");

    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int a, b, c;
        fin >> a >> b >> c;
        graph[a].emplace_back(b, c);
    }

    for (int i = 1; i <= n; ++i) {
        dist[i] = INF;
    }

    dist[1] = 0;
    vis[1] = true;
    q.push(1);
    while (!q.empty()) {

        int node = q.front();
        q.pop();

        for (auto i : graph[node]) {
            int next = i.first;
            int cost = i.second;
            if (dist[node] + cost < dist[next]) {
                dist[next] = dist[node] + cost;
                if (!vis[next]) {
                    vis[next] = true;
                    q.push(next);
                    cicle[next]++;
                    if (cicle[next] >= n) {
                        fout << "Ciclu negativ!";
                        return 0;
                    }
                }
            }
        }
        vis[node] = false;
    }


    for (int i = 2; i <= n; ++i) {
        fout << dist[i] << " ";
    }

    return 0;
}