Cod sursa(job #3336355)

Utilizator CalinHanguCalinHangu CalinHangu Data 24 ianuarie 2026 16:54:31
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.49 kb
#include <iostream>
#include <vector>
#include <algorithm>
#define pii pair<int, int>

using namespace std;

const int NMAX = 5 * 1e5 + 5;
const char nl = '\n';
const int INF = 1e9 + 7;

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

vector<pii> graph[NMAX];
vector<edge> edges;
int dist[NMAX];

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

    dist[source] = 0;
    for(int i = 1; i < n; ++i) {
        for(auto edg: edges) {
            if(dist[edg.u] == INF) {
                continue;
            }
                
            if(dist[edg.v] > dist[edg.u] + edg.weight) {
                dist[edg.v] = dist[edg.u] + edg.weight;
            }
        }
    }

    bool cycle = false;
    for(auto edg: edges) {
        if(dist[edg.v] > dist[edg.u] + edg.weight) {
            cycle = true;
            break;
        }
    }

    if(cycle) {
        cout << "Ciclu negativ!" << nl;
    } else {
        for(int i = 2; i <= n; ++i) {
            cout << dist[i] << ' ';
        }
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    freopen("bellmanford.in", "r", stdin);
    freopen("bellmanford.out", "w", stdout);

    int n, m;
    cin >> n >> m;

    for(int i = 0; i < m; ++i) {
        int u, v, w;
        cin >> u >> v >> w;

        graph[u].push_back({v, w});
        edges.push_back({u, v, w});
    }
    bellmanford(1, n);
    return 0;
}