Cod sursa(job #3313985)

Utilizator mirceamaierean41Mircea Maierean mirceamaierean41 Data 7 octombrie 2025 18:14:34
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.42 kb
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;
typedef pair<int, int> pii;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

const int NMAX = 5e4 + 1;
const int oo = 0x3f3f3f3f;

vector<pii> g[NMAX];
vector<int> dist;

// struct cmp
// {
//     inline bool operator()(const int &x, const int &y)
//     {
//         return dist[x] > dist[y];
//     }
// };

void dijkstra(int start)
{
    // priority_queue<int, vector<int>, cmp> pq; // ok
    // retinem in pq valori de tipul {cost, nod};
    priority_queue<pii, vector<pii>, greater<pii>> pq;
    fill(dist.begin(), dist.end(), oo);
    pq.push({0, start});

    while (!pq.empty())
    {
        auto p = pq.top();
        pq.pop();

        if (dist[p.second] != oo) // deja am procesat nodul p.second, deci pur si simplu sarim peste
            continue;

        dist[p.second] = p.first;

        for (auto &x : g[p.second])
            if (dist[x.first] == oo && dist[p.second] + x.second < dist[x.first])
                pq.push({dist[p.second] + x.second, x.first});
    }
}

int main()
{
    int n, m;
    fin >> n >> m;

    int x, y, c;
    for (int i = 1; i <= m; ++i)
    {
        fin >> x >> y >> c;
        g[x].push_back({y, c});
    }

    dist.resize(n + 1, 0);

    dijkstra(1);

    for (int i = 2; i <= n; ++i)
    {
        if (dist[i] == oo)
            dist[i] = 0;
        fout << dist[i] << " ";
    }
    return 0;
}