Cod sursa(job #3270783)

Utilizator THEO0808Teodor Lepadatu THEO0808 Data 24 ianuarie 2025 14:20:40
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>

const int lmax = 50000;
const int INF = 2000000000;
std::vector<std::pair<int, int>> adj[lmax + 1];
int dist[lmax + 1];

std::vector<int> dijkstra(int s, int n) {
    std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, std::greater<std::pair<int, int>>> pq;
    std::fill(dist, dist + n + 1, INF);

    dist[s] = 0;
    pq.push({0, s});

    while (!pq.empty()) {
        int u = pq.top().second;
        int d = pq.top().first;
        pq.pop();

        if (d > dist[u]) continue;

        for (auto edge : adj[u]) {
            int v = edge.first, weight = edge.second;
            if (dist[u] + weight < dist[v]) {
                dist[v] = dist[u] + weight;
                pq.push({dist[v], v});
            }
        }
    }

    std::vector<int> result;
    for (int i = 2; i <= n; i++) {
        result.push_back(dist[i] == INF ? 0 : dist[i]);
    }
    return result;
}

int main() {
    std::ifstream fin("dijkstra.in");
    std::ofstream fout("dijkstra.out");

    int n, m;
    fin >> n >> m;

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

    std::vector<int> shortest_paths = dijkstra(1, n);
    for (int d : shortest_paths) {
        fout << d << ' ';
    }

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