Cod sursa(job #2767545)

Utilizator vlad2009Vlad Tutunaru vlad2009 Data 6 august 2021 17:36:45
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.38 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

const int Nmax = 50000;
const int INF = (1 << 30);
int dist[Nmax + 1];
bool viz[Nmax + 1];
vector <pair <int, int>> adj[Nmax + 1];
queue <int> q;
int cnt[Nmax + 1];

int main()
{
    ifstream fin("bellmanford.in");
    ofstream fout("bellmanford.out");
    int n, m;
    fin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int u, v, w;
        fin >> u >> v >> w;
        adj[u].push_back({v, w});
    }
    for (int i = 1; i <= n; i++)
    {
        dist[i] = INF;
    }
    dist[1] = 0;
    q.push(1);
    viz[1] = true;
    while (!q.empty())
    {
        int s = q.front();
        q.pop();
        viz[s] = false;
        for (auto u : adj[s])
        {
            int to = u.first, len = u.second;
            if (dist[s] + len < dist[to])
            {
                dist[to] = dist[s] + len;
                if (!viz[to])
                {
                    q.push(to);
                    viz[to] = true;
                    cnt[to]++;
                    if (cnt[to] > n)
                    {
                        fout << "Ciclu negativ!";
                        return 0;
                    }
                }
            }
        }
    }
    for (int i = 2; i <= n; i++)
    {
        fout << dist[i] << " ";
    }
    return 0;
}