Cod sursa(job #2780445)

Utilizator ps2001Silviu Popescu ps2001 Data 6 octombrie 2021 23:34:50
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <bits/stdc++.h>

using namespace std;

const int INF = 0x3f3f3f3f;

int main()
{
    ifstream fin("dijkstra.in");
    ofstream fout("dijkstra.out");

    int n, m;
    fin >> n >> m;

    vector<vector<pair<int, int>>> gr(n + 1);

    for (int i = 0; i < m; i++) {
        int u, v, c;
        fin >> u >> v >> c;

        gr[u].emplace_back(v, c);
        gr[v].emplace_back(u, c);
    }

    set<pair<int, int>> s;
    vector<int> d(n + 1, INF);

    int start = 1;

    d[start] = 0;
    s.insert({0, start});

    while (s.size() != 0) {
        int node, cost;
        tie(cost, node) = *s.begin();
        s.erase(s.begin());

        //if (cost != d[node]) continue;

        for (auto &x : gr[node]) {
            if (cost + x.second < d[x.first]) {
                if (d[node] != INF)
                    s.erase(make_pair(d[node], node));
                    
                d[x.first] = cost + x.second;
                s.insert({d[x.first], x.first});
            }
        }
    }

    //cout << "Vectorul de distante plecand din " << start << '\n';
    for (int i = 2; i <= n; i++) {
        if (d[i] == INF) d[i] = 0;
        fout << d[i] << ' ';
    }

    fout << '\n';
    return 0;
}