Cod sursa(job #3325319)

Utilizator h4rap-a1bMihail Cosor h4rap-a1b Data 25 noiembrie 2025 12:23:08
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.58 kb
//
// Created by h4rapa1b on 11/25/25.
//
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

const int INF = 2000000000;
int main() {
    ifstream fin("dijkstra.in");
    ofstream fout("dijkstra.out");

    int n, m;
    fin >> n >> m;
    vector<vector<pair<int, int>>> graph(n + 1);

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

    // init vector distante si coada de prioritati
    vector<int> dist(n + 1, INF);
    dist[1] = 0;
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;

    // adaugam nodul de start in coada
    pq.push({0, 1});
    while (!pq.empty()) {
        // extrage nod cu dist minima
        int u = pq.top().second;
        int curr_dist = pq.top().first;
        pq.pop();

        // daca distanta gasita e mai mare decat distanta inregistrata, sarim peste
        if (curr_dist > dist[u]) {
            continue;
        }

        // relaxam muchiile adiacente
        for (auto &edge : graph[u]) {
            int v = edge.first;
            int cost = edge.second;

            // daca am gasit o distanta mai mica, actualizam si adaugam in coada
            if (dist[u] + cost < dist[v]) {
                dist[v] = dist[u] + cost;
                pq.push({dist[v], v});
            }
        }
    }

    // afisam distantele
    for (int i = 2; i <= n; ++i) {
        if (dist[i] == INF) {
            fout << 0 << " ";
        } else {
            fout << dist[i] << " ";
        }
    }

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