Cod sursa(job #2954060)

Utilizator AleXutzZuDavid Alex Robert AleXutzZu Data 13 decembrie 2022 09:24:38
Problema Algoritmul lui Dijkstra Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.4 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

int main() {
    std::ifstream input("dijkstra.in");
    std::ofstream output("dijkstra.out");

    int n, m;
    input >> n >> m;

    std::vector<std::vector<std::pair<int, int>>> graph;

    graph.resize(n);

    for (int i = 0; i < m; ++i) {
        int a, b, c;
        input >> a >> b >> c;
        graph[a].emplace_back(b, c);
    }

    std::vector<int> dist(n + 1, INT32_MAX);
    std::vector<bool> visited(n + 1, false);
    dist[1] = 0;


    auto cmp = [](const std::pair<int, int> &_lhs, const std::pair<int, int> &_rhs) {
        return _lhs.second > _rhs.second;
    };

    std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, decltype(cmp)> queue(cmp);

    queue.emplace(1, 0);
    visited[1] = true;
    while (!queue.empty()) {
        int current = queue.top().first;
        if (queue.top().second > dist[current]) {
            queue.pop();
            continue;
        }
        queue.pop();

        for (const auto &x: graph[current]) {
            int candidate = x.second + dist[current];
            if (dist[x.first] > candidate) {
                dist[x.first] = candidate;

                queue.emplace(x.first, dist[x.first]);
            }
        }
    }

    for (int i = 2; i <= n; ++i) {
        if (dist[i] == INT32_MAX) dist[i] = 0;
        output << dist[i] << " ";
    }

    return 0;
}