Cod sursa(job #3191151)

Utilizator vvvvvvvvvvvvvVusc David vvvvvvvvvvvvv Data 8 ianuarie 2024 21:47:33
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.16 kb
#include <fstream>
#include <queue>

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
const int INF = 99999999999;
int n, m, start, d[50001], ant[50001];
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
vector<pair<int, int>> g[50001];

void djikstra(int s){
    for(int i = 1; i <= n; i++) d[i] = INF;
    pq.push({0, s});
    d[s] = 0;
    while(!pq.empty()){
        int u = pq.top().second, c1 = pq.top().first;
        pq.pop();

        if(d[u] == c1){
            for(auto v : g[u]){
                int c = v.second, nod = v.first;
                if(c + d[u] < d[nod]){
                    d[nod] = c + d[u];
                    ant[nod] = u;
                    pq.push({d[nod], nod});
                }
            }
        }
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++){
        int x, y, c;
        fin >> x >> y >> c;
        g[x].push_back({y, c});
    }
    djikstra(1);
    for(int i = 2; i <= n; i++)
        if(d[i] == INF) fout << 0 << ' ';
        else fout << d[i] << ' ';
    fin.close();
    fout.close();
    return 0;
}