Cod sursa(job #3125918)

Utilizator SergetecLefter Sergiu Sergetec Data 4 mai 2023 19:31:03
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.42 kb
/*
 * Lefter Sergiu - 04/05/2023
*/
#include <fstream>
#include <vector>
#include <climits>
#include <queue>

using namespace std;

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

const int N = 5e4;
const int INF = INT_MAX;

struct succesor {
    int vf, c;
};

vector <succesor> s[N+1];
bool selectat[N+1];
int n, m, d[N+1];

void dijkstra(int x0) {
    priority_queue <pair <int, int>> pq;
    for (int i = 1; i <= n; ++i) {
        d[i] = INF;
        selectat[i] = false;
    }
    d[x0] = 0;
    pq.push({0, x0});
    while (!pq.empty()) {
        int x = pq.top().second;
        pq.pop();
        if (selectat[x]) {
            continue;
        }
        selectat[x] = true;
        for (auto p: s[x]) {
            int y = p.vf;
            int c = p.c;
            if (selectat[y]) { //daca a fost selectat nu il mai bagam in seama
                continue;
            }
            if (d[x] + c < d[y]) {
                d[y] = d[x] + c;
                pq.push({-d[y], y});
            }
        }
    }
}

int main() {
    in >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int x, y, c;
        in >> x >> y >> c;
        s[x].push_back((succesor){y, c});
    }
    dijkstra(1);
    for (int i = 2; i <= n; ++i) {
        if (d[i] == INF) {
            d[i] = -1;
        }
        out << d[i] << " ";
    }
    in.close();
    out.close();
    return 0;
}