Cod sursa(job #3270791)

Utilizator THEO0808Teodor Lepadatu THEO0808 Data 24 ianuarie 2025 14:55:00
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.23 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>

const int lmax = 50000;
const int INF = 1000000000;

struct Edge {
    int u, v, weight;
};

std::vector<Edge> edges;
int dist[lmax + 1];

bool bellman_ford(int s, int n) {
    std::fill(dist, dist + n + 1, INF);
    dist[s] = 0;

    for (int i = 1; i <= n - 1; i++) {
        for (auto edge : edges) {
            if (dist[edge.u] != INF && dist[edge.u] + edge.weight < dist[edge.v]) {
                dist[edge.v] = dist[edge.u] + edge.weight;
            }
        }
    }

    for (auto edge : edges) {
        if (dist[edge.u] != INF && dist[edge.u] + edge.weight < dist[edge.v]) {
            return false;  // Ciclu negativ detectat
        }
    }
    return true;
}

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

    int n, m;
    fin >> n >> m;

    for (int i = 0; i < m; i++) {
        int u, v, w;
        fin >> u >> v >> w;
        edges.push_back({u, v, w});
    }

    if (!bellman_ford(1, n)) {
        fout << "Ciclu negativ!";
    } else {
        for (int i = 2; i <= n; i++) {
            fout << (dist[i] == INF ? 0 : dist[i]) << ' ';
        }
    }

    fin.close();
    fout.close();
    return 0;
}