Cod sursa(job #1657642)

Utilizator mihai.constantinConstantin Mihai mihai.constantin Data 20 martie 2016 17:36:03
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include <iostream>
#include <fstream>
#include <queue>
using namespace std;

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

const int N_max = 50002;
const int INF = 250000005;

vector < pair <int, int> > graph[N_max];

int dmin[N_max];

class cmp
{
    public:
        bool operator () (int x, int y) const
        { return dmin[x] > dmin[y]; }
};

priority_queue < int, vector<int>, cmp > H;

int N, M;

void read()
{
    int x, y, c;

    in >> N >> M;

    for(int i = 1; i <= M; i++)
    {
        in >> x >> y >> c;

        // GRAF ORIENTAT
        graph[x].push_back( make_pair(y, c) );
    }
}

void dijkstra(int node)
{
    int i, x, y, cost;

    for(i = 1; i <= N; i++) dmin[i] = INF;

    // INSEREZ NODUL DE START
    H.push(node);
    dmin[node] = 0;

    while( !H.empty() )
    {
        x = H.top();
        H.pop();

        for(i = 0; i < graph[x].size(); i++)
        {
            y = graph[x][i].first;
            cost = graph[x][i].second;

            if(dmin[y] > dmin[x] + cost)
            {
                dmin[y] = dmin[x] + cost;

                H.push(y);
            }
        }
    }
}

void write()
{
    for(int i = 2; i <= N; i++) out << dmin[i] << " ";
}

int main()
{
    read();

    dijkstra(1);

    write();

    return 0;
}