Cod sursa(job #2691653)

Utilizator andrei_laurentiuRadu Andrei-Laurentiu andrei_laurentiu Data 29 decembrie 2020 15:27:46
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <iostream>
#include <queue>
#include <fstream>

using namespace std;

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

const int nmax = 50005, val_mare = 20000*50000;
vector<pair<int, int> > list_vec[nmax];
int dist[nmax], in_coada[nmax], n, m;

struct cmp
{
    bool operator() (int x, int y)
    {
        return dist[x] > dist[y];
    }
};
priority_queue<int, vector<int>, cmp > pq;

void dijkstra(int start)
{
    int cost, curent, vecin;

    for(int i = 1; i <= n; ++i)
        dist[i] = val_mare;
    dist[start] = 0;
    in_coada[start] = 1;
    pq.push(start);

    while(!pq.empty())
    {
        curent = pq.top();
        pq.pop();
        in_coada[curent] = 0;
        for(auto a : list_vec[curent])
        {
            vecin = a.first;
            cost = a.second;
            if(dist[vecin] > dist[curent] + cost)
            {
                dist[vecin] = dist[curent] + cost;
                if(!in_coada[vecin])
                {
                    in_coada[vecin] = 1;
                    pq.push(vecin);
                }
            }
        }
    }
}
int main()
{
    int i, j, u, v, c;

    fin>>n>>m;
    for(i = 1; i <= m; ++i)
    {
        fin>>u>>v>>c;
        list_vec[u].push_back({v, c});
    }

    dijkstra(1);
    for(i = 2; i <= n; ++i)
    {
        if(dist[i] != val_mare)
            fout<<dist[i]<<' ';
        else
            fout<<0<<' ';
    }
    return 0;
}