Cod sursa(job #2681339)

Utilizator BeilandArnoldArnold Beiland BeilandArnold Data 5 decembrie 2020 11:49:35
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

const int INF = 1 << 30;


vector<int> dijkstra(int start, int n, const vector<vector<pair<int,int>>> &adj)
{
    vector<int> dist(n+1, INF);
    dist[start] = 0;

    priority_queue<pair<int,int>, deque<pair<int,int>>, greater<pair<int,int>> > q;
    q.push({0,start});

    while (!q.empty()) {
        auto best = q.top();
        int du = best.first;
        int u = best.second;

        q.pop();

        if (du != dist[u]) continue;

        for (auto p : adj[u]) {
            int v = p.second;
            int edge = p.first;

            if (dist[v] > du + edge) {
                dist[v] = du + edge;
                q.push({dist[v], v});
            }
        }
    }


    return dist;
}


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

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

    vector<vector<pair<int,int>>> adj(n+1);
    for (int i = 0; i < m; ++i) {
        int x,y,cost;
        fin >> x >> y >> cost;

        adj[x].push_back({ cost, y });
    }

    auto dist = dijkstra(1,n,adj);
    for (int i = 2; i <= n; ++i)
        fout << dist[i] << ' ';
    fout << endl;

    return 0;
}