Cod sursa(job #1260636)

Utilizator mlupseLupse-Turpan Mircea mlupse Data 11 noiembrie 2014 14:05:55
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.79 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <list>
#define NMax 50005
#define CMax 50005
#define oo 50001
using namespace std;

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

int N,M;
vector < pair <int,int> > G[NMax];
list <int> L[CMax];
list <int> :: iterator A[NMax];
int D[NMax];

void Read()
{
    fin>>N>>M;
    for(int i=1;i<=M;i++)
    {
            int x,y,c;
            fin>>x>>y>>c;
            G[x].push_back(make_pair(y,c));
    }
}

void Init()
{
    for(int i=2;i<=N;i++)
    {
        D[i]=oo;
        L[oo].push_back(i);
    }

    int Node=2;
    for(list <int> :: iterator it = L[oo].begin();it!=L[oo].end();it++)
        A[Node++]=it;

    L[0].push_back(1);
    A[1] = L[0].begin();

}

void Dijkstra()
{
        Init();
        for(int i = 0 ; i < oo; i++)
            {
            while (!L[i].empty())
                {
                int Nod = L[i].front(); L[i].pop_front();
                for(unsigned int j = 0; j< G[Nod].size();j++)
                    {
                    int Vecin = G[Nod][j].first;
                    int Cost  = G[Nod][j].second;
                    if(D[Vecin] > D[Nod] + Cost)
                        {

                            L[D[Vecin]].erase(A[Vecin]);
                            D[Vecin] = D[Nod] + Cost;
                            L[D[Vecin]].push_back(Vecin);
                            A[Vecin]=--L[D[Vecin]].end();

                        }
                    }
                }
            }
}

void Print()
{
    for(int i=2;i<=N;i++)
        if(D[i]==oo)
            D[i]=0;
    for(int i=2;i<=N;i++)
        fout<<D[i]<<" ";
    fout<<"\n";
}

int main()
{
        Read();
        Dijkstra();
        Print();
    return 0;
}