Cod sursa(job #2046718)

Utilizator radu.leonardoThe Doctor radu.leonardo Data 24 octombrie 2017 01:29:51
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.22 kb
#include <bits/stdc++.h>
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
int N, M;
int D[50001];
vector<pair<int, int>> G[50001];
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> PQ;
void Read() {
    f >> N >> M;
    for (int i = 1; i <= M; i++) {
        int x, y, c;
        f >> x >> y >> c;
        G[x].push_back({c, y});
        G[y].push_back({c, x});
    }
}
void Dijkstra() {
    D[1] = 0;
    for (int i = 2; i <= N; i++) D[i] = -1;
    for (auto it:G[1])
        PQ.push(it),
                D[it.second] = it.first;
    while (!PQ.empty()) {
        pair<int, int> current = PQ.top();
        PQ.pop();
        for (auto next:G[current.second])
            if (D[next.second]==-1 && D[next.second] > D[current.second] + next.first)
                D[next.second] = D[current.second] + next.first,
                        PQ.push(next);    }
    for (int i = 2; i <= N; i++)      if (D[i] == INT_MAX) g << "0 ";
        else g << D[i] << ' ';
}
int main() {
    Read();
    Dijkstra();
}