Cod sursa(job #1750054)

Utilizator topala.andreiTopala Andrei topala.andrei Data 29 august 2016 15:34:44
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;
const int maxn = 50001;
const int inf = 1 << 30;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
vector <pair<int,int> >h;
int d[maxn],poz[maxn];
int n,m;
vector <int>a[maxn],cost[maxn];
void citire()
{
    f>>n>>m;

    int x, y, z;
    for ( int i = 1; i <= m; ++i )
    {
        f>>x>>y>>z;
        a[x].push_back(y);
        cost[x].push_back(z);
    }
}
void dijkstra_heap(int x)
{
    for ( int i = 1; i <= n; ++i )
        d[i] = inf;
    h.push_back(make_pair(0, 1));
    int nod,next;
    long long cdist;
    while (!h.empty())
    {
        nod = h[0].second;
        cdist=-h[0].first;
        pop_heap(h.begin(), h.end());
        h.pop_back();

        for(int i=0; i<a[nod].size(); ++i)
        {
            next=a[nod][i];
            if(d[next]>cdist+cost[nod][i])
            {
                d[next]=cdist+cost[nod][i];
                h.push_back(make_pair(-d[next], next));
                push_heap(h.begin(), h.end());
            }
        }
    }
}
int main()
{
    citire();
    dijkstra_heap(1);
    for ( int i = 2; i <= n; ++i )
        if (d[i]==inf) g<<0<<" ";
        else g<<d[i]<<" ";
}