Cod sursa(job #2505661)

Utilizator MarianConstantinMarian Constantin MarianConstantin Data 7 decembrie 2019 10:11:52
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.42 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <set>
#define pb push_back

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijktra.out");
const int MAXN = 50010;
const int INF = 0x3f3f3f3f;

struct Node {
    int node, cost;
    bool operator<(const Node &other) const {
        if (cost != other.cost)
            return cost < other.cost;
        return node < other.node;
    }
};

int n, m, dist[MAXN];
vector<Node> edges[MAXN];
set<Node> heap;

void read() {
    fin >> n >> m;
    for (int i = 0; i < m; ++i) {
        int x, y, c;
        fin >> x >> y >> c;
        edges[x].pb({y, c});
    }
}

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

void dijkstra() {
    dist[1] = 0;
    heap.insert({1, 0});
    while (!heap.empty()) {
        int node = heap.begin()->node;
        heap.erase(heap.begin());
        for (const auto &it: edges[node])
            if (dist[it.node] > dist[node] + it.cost) {
                if (dist[it.node] != INF)
                    heap.erase({it.node, dist[it.node]});
                dist[it.node] = dist[node] + it.cost;
                heap.insert({it.node, dist[it.node]});
            }
    }
}

void print() {
    for (int i = 2; i <= n; ++i)
        fout << dist[i] << ' ';
}

int main() {
    read();
    initialize();
    dijkstra();
    print();
    return 0;
}