Cod sursa(job #2755573)

Utilizator George_CristianGeorge Dan-Cristian George_Cristian Data 27 mai 2021 18:22:09
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <fstream>
#include <vector>
#include <bitset>
#include <queue>

using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

#define NMAX 50005
#define INF 1000000000

int n, m;
vector<pair<int, int>> G[NMAX];
int d[NMAX], t[NMAX];
bitset<NMAX> viz;
priority_queue<pair<int, int>> q;

void citire() {
    f >> n >> m;
    int nod1, nod2, cost;
    for (int i = 0; i < m; i++) {
        f >> nod1 >> nod2 >> cost;
        G[nod1].push_back({cost, nod2});
    }
}

void initializare() {
    for (int i = 2; i <= n; i++)
        d[i] = INF;
}

void parcurgere() {
    int vf = 1;
    while (true) {
        viz[vf] = true;
        for (auto &nod:G[vf])
            if (!viz[nod.second] && d[vf] + nod.first < d[nod.second]) {
                d[nod.second] = d[vf] + nod.first;
                q.push({-d[nod.second], nod.second});
                t[nod.second] = vf;
            }
        while (!q.empty() && viz[q.top().second])
            q.pop();
        if (q.empty())
            break;
        vf = q.top().second;
    }
}

void afisare() {
    for (int i = 2; i <= n; i++) {
        if (d[i] == INF)
            g << 0 << ' ';
        else
            g << d[i] << ' ';
    }
}

int main() {
    citire();
    initializare();
    parcurgere();
    afisare();
    return 0;
}