Cod sursa(job #2562926)

Utilizator mihai03Mihai Grigore mihai03 Data 29 februarie 2020 20:11:52
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.48 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
const int nmax = 50005;
const int inf = (1 << 30);

int d[nmax];

struct comparaDistante
{
    bool operator() (int x, int y)
    {
        return d[x] > d[y];
    }
};

int n, m;
vector < pair < int , int > > G[nmax];
bool inQueue[nmax];
priority_queue < int , vector < int >, comparaDistante> q;

void Dijkstra(int startNode)
{
    for(int i = 1; i <= n; i++)
    {
        d[i] = inf;
    }
    d[startNode] = 0;
    inQueue[startNode] = true;
    q.push(startNode);
    while(!q.empty())
    {
        int nodCurent = q.top();
        q.pop();
        for(int i = 0; i < G[nodCurent].size(); i++)
        {
            int vecin = G[nodCurent][i].first;
            int cost = G[nodCurent][i].second;
            if(d[nodCurent] + cost < d[vecin])
            {
                d[vecin] = d[nodCurent] + cost;
                if(inQueue[vecin] == false)
                {
                    inQueue[vecin] = true;
                    q.push(vecin);
                }
            }
        }
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int a, b, c;
        fin >> a >> b >> c;
        G[a].push_back(make_pair(b, c));
    }

    // here goes dijkstra
    Dijkstra(1);

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