Cod sursa(job #3333772)

Utilizator ioan19Buzdugan Ioan-Michael ioan19 Data 15 ianuarie 2026 07:59:06
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.49 kb
#include <bits/stdc++.h>
using namespace std;

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

const int nmax = 50005;
const int inf = INT_MAX;

struct muchie {
    int y, c;
};

vector<muchie> adj[nmax];
int dist[nmax];
int nr[nmax];     
bool in_queue[nmax]; 
int n, m;

bool bellman_ford(int start_node) {
    queue<int> q;

    for (int i = 1; i <= n; i++) {
        dist[i] = inf;
        in_queue[i] = false;
        nr[i] = 0;
    }

    dist[start_node] = 0;
    q.push(start_node);
    in_queue[start_node] = true;

    while (!q.empty()) {
        int x = q.front();
        q.pop();
        in_queue[x] = false;

        for (auto it : adj[x]) {
            int y = it.y;
            int c = it.c;

            if (dist[y] > dist[x] + c) {
                dist[y] = dist[x] + c;
                
                if (!in_queue[y]) {
                    q.push(y);
                    in_queue[y] = true;
                    nr[y]++;

                    if (nr[y] >= n) {
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

int main() {
    f >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y, c;
        f >> x >> y >> c;
        adj[x].push_back({y, c});
    }

    if (!bellman_ford(1)) {
        g << "Ciclu negativ!";
    } else {
        for (int i = 2; i <= n; i++) {
            g << dist[i] << " ";
        }
    }

    return 0;
}