Cod sursa(job #3231802)

Utilizator adimiclaus15Miclaus Adrian Stefan adimiclaus15 Data 27 mai 2024 19:38:05
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.25 kb
//O(M * log(N))

#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 50000;
const int INF = 1e9;
vector<pair<int, int>> G[NMAX + 1];
int d[NMAX + 1], use[NMAX + 1];
set<pair<int, int>> s; // perechi de forma (d[nod], nod)


int main() {
    int n, m;
    f >> n >> m;
    for(int i = 1; i <= m; i++) {
        int x, y, z;
        f >> x >> y >> z;
        G[x].push_back({y, z});
    }
    for(int i = 1; i <= n; i++) {
        d[i] = INF;
    }
    d[1] = 0; //d[sursa] = 0;
    s.insert({0, 1});
    while(!s.empty()) {
        pair<int, int> p = *s.begin(); // aflam minimul in log(N)
        s.erase(p);
        int node = p.second;
        if(use[node] == 1) {
            continue;
        }
        use[node] = 1;
        for(int j = 0; j < G[node].size(); j++) {
            int next = G[node][j].first;
            int cost = G[node][j].second;
            if(d[next] > d[node] + cost) {
                d[next] = d[node] + cost;
                s.insert({d[next], next});
            }
        }
    }
    for(int i = 2; i <= n; i++) {
        if(d[i] == INF) {
            g << 0 << ' ';
        } else {
            g << d[i] << ' ';
        }
        //g << d[i] << ' ';
    }
    return 0;
}