Cod sursa(job #2901007)

Utilizator IVVladIon Vlad Vasile IVVlad Data 12 mai 2022 18:58:57
Problema Algoritmul lui Dijkstra Scor 70
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.41 kb
#include <fstream>
	
#include <vector>
	
#include <queue>
	
using namespace std;
	
ifstream f("dijkstra.in");
	
ofstream g("dijkstra.out");
	
const int NMax = 50005;
	
const int oo = (1 << 30);
	
int N,M;
	
int D[NMax];
	
bool viz[NMax];
	
vector < pair <int,int> > G[NMax];
	
struct compara
	
{
	
    bool operator() (int x,int y)
	
    {
	
        return D[x]>D[y];
	
    }
	
};
	
priority_queue<int, vector<int>, compara> coada;
	
void citire()
	
{
	
    f>>N>>M;
	
    for(int i=1; i<=M; i++)
	
    {
	
        int x,y,c;
	
        f>>x>>y>>c;
	
        G[x].push_back(make_pair(y,c));
	
    }
	
}
	
void Dijkstra(int nod)
	
{
	
    for(int i=1; i<=N; i++)
	
        D[i]=oo;
	
    D[nod]=0;
	
    coada.push(nod);
	
    while(!coada.empty())
	
    {
	
        int nodcurent=coada.top();
	
        coada.pop();

        viz[nodcurent] = 1;
	
        for(size_t i=0; i<G[nodcurent].size(); i++)
	
        {
	
            int vecin=G[nodcurent][i].first;
	
            int cost=G[nodcurent][i].second;
	
            if(D[vecin]>D[nodcurent]+cost)
	
            {
	
                D[vecin]=D[nodcurent]+cost;
	
            }

            if(!viz[vecin])
                    coada.push(vecin);
	
        }
	
    }
	
}
	
void afisare()
	
{
	
    for(int i=2; i<=N; i++)
	
    {
	
        if(D[i]!=oo)g<<D[i]<<" ";
	
        else g<<0<<" ";
	
    }
	
}
	
int main()
	
{
	
    citire();
	
    Dijkstra(1);
	
    afisare();
	
    return 0;
	
}