Cod sursa(job #3325487)

Utilizator Mirc100Mircea Octavian Mirc100 Data 25 noiembrie 2025 16:34:03
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.33 kb
#include <iostream>
#include <vector>
#include <queue>
#define pii pair<int, int>
using namespace std;

const int NMAX = 5e5 + 5; // 5 * 10^ 5 + 5
const char nl = '\n';
const int INF = 1e9 + 7; // 10 ^ 9 + 7

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

void dijkstra(int source, int size) {
    for(int i = 1; i <= size; ++i) {
        dist[i] = INF;
    }

    priority_queue<pii> pq;
    dist[source] = 0;
    pq.push({0, source});
    while(!pq.empty()) {
        int cur_node = pq.top().second;
        int cur_weight = pq.top().first;
        pq.pop();

        for(auto neigh: g[cur_node]) {
            if(dist[neigh.first] > dist[cur_node] + neigh.second) {
                dist[neigh.first] = dist[cur_node] + neigh.second;
                pq.push({-dist[neigh.first], neigh.first}); // prima e distanta
            }
        }
    }
}

int main()
{
    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);

    int n, m;
    cin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int u, v, w;
        cin >> u >> v >> w;
        g[u].push_back({v, w}); // graf orientat
    }

    dijkstra(1, n);

    for(int i = 2; i <= n; ++i) {
        if(dist[i] == INF) {
            cout << 0 << ' ';
        } else {
            cout << dist[i] << ' ';
        }
    }
    return 0;
}