Cod sursa(job #2857481)

Utilizator albuAlbu Victor albu Data 25 februarie 2022 17:53:20
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.16 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream cin("dijkstra.in");
ofstream cout("dijkstra.in");
const int MAX = 50001, INF = 1e9;
vector<pair<int, int> > gr[MAX];
queue<int> q;
int n, m, d[MAX], f[MAX];
int bellman() {
    for(int i = 2; i <= n; ++i) {
        d[i] = INF;
    }
    q.push(1);
    while(!q.empty()) {
        int u = q.front();
        q.pop();
        for(int i = 0; i < gr[u].size(); ++i) {
            int v = gr[u][i].first;
            int w = gr[u][i].second;
            if(d[u] + w < d[v]) {
                d[v] = d[u] + w;
                q.push(v);
                ++f[v];
                if(f[v] == n) {
                    return -1;
                }
            }
        }
    }
    return 0;
}
int main()
{
    cin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        gr[u].push_back({v, w});
    }
    if(bellman() == -1) {
        cout << "Ciclu negativ!";
    } else {
        for(int i = 2; i <= n; ++i) {
            if(d[i]==INF)cout<<0<<' ';
            else cout << d[i] << ' ';
        }
    }
    return 0;
}