Cod sursa(job #2425810)

Utilizator ZamfiAndreiZamfira Andrei ZamfiAndrei Data 25 mai 2019 03:57:19
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <fstream>
#include <list>
#include <queue>

using namespace std;

#define INF (1<<25)

void Dijkstra(int source, int vertices, list<pair<int, int>> *adj) {
    ofstream g("dijkstra.out");
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> priorityQueue;
    vector<int> dist (vertices, INF);
    vector<bool> ext(vertices, false);

    priorityQueue.push(make_pair(0, source));
    dist[source] = 0;

    while (!priorityQueue.empty()) {
        int u = priorityQueue.top().second;
        priorityQueue.pop();

        if (ext[u]) continue;
        ext[u] = true;

        list<pair<int, int>>::iterator i;
        for (i = adj[u].begin(); i != adj[u].end(); ++i) {
            int v = (*i).first;
            int weight = (*i).second;

            if (dist[v] > dist[u] + weight) {
                dist[v] = dist[u] + weight;
                priorityQueue.push(make_pair(dist[v], v));
            }
        }
    }

    for (int i = 1; i < vertices; i++) {
        if (dist[i] == INF) {
            g << 0 << " ";
        } else {
            g << dist[i] << " ";
        }
    }
}

int main() {
    ifstream f("dijkstra.in");
    int vertices, edges, from, to, weight;
    f >> vertices >> edges;
    list<pair<int, int>> *adj = new list<pair<int, int>> [vertices];

    for (int i = 0; i < edges; i++) {
        f>>from;
        f>>to;
        f>>weight;
        adj[from - 1].push_back(make_pair(to - 1, weight));
    }

    Dijkstra(0, vertices, adj);
}