Cod sursa(job #1237723)

Utilizator dianaa21Diana Pislaru dianaa21 Data 4 octombrie 2014 18:45:07
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
#include <vector>
#include <queue>
#define INF 0x3f3f3f
using namespace std;

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

vector <pair<int, int> > V[50001];
priority_queue < pair<int,int>, vector< pair<int,int> >, greater <pair<int,int> > > Q;
vector <int> d;
int n, m;

void Read();
void Dijkstra();

int main()
{
    Read();
    Dijkstra();
    for(int i = 2; i <= n; ++i)
    {
        if(d[i] == INF)
            os << 0 << ' ';
        else
            os << d[i] << ' ';
    }

    is.close();
    os.close();
    return 0;
}
void Read()
{
    int a, b, c;
    is >> n >> m;
    for(int i = 1; i <= m; ++i)
    {
        is >> a >> b >> c;
        V[a].push_back({c, b});
    }
    d.resize(n+1, INF);
    d[1] = 0;
    Q.push({0, 1});
}
void Dijkstra()
{
    int dist, nod;
    while(!Q.empty())
    {
        dist = Q.top().first;
        nod = Q.top().second;
        Q.pop();
        vector<pair<int,int> >::iterator it;
        for(it = V[nod].begin(); it != V[nod].end(); ++it)
            if( d[it->second] > dist + it->first)
            {
                d[it->second] = dist + it->first;
                Q.push({d[it->second], it->second});
            }
    }
}