#include <iostream>
#include <stdlib.h>
#include "mpi.h"

using namespace std;

int main(int argc, char**argv)
{
  MPI_Init(&argc, &argv);

    int rank, size;

    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);

    int rozmiar;
    int nRank;
    int maxRank;
    int maxAll;


    if(rank == 0)   // pierwszy rank
    {
      cout<<"Podaj rozmiar tablicy: ";
      cin>>rozmiar;
      srand (time(NULL));
      int * tab = new int[rozmiar];
      for(int i = 0; i<rozmiar; ++i)
    {
    tab[i]=rand() % 100;
    }

    cout<<"ILOSC PROCESOW: "<<size<<endl;

      int nRank = rozmiar / size;
      cout<<"Rozmiar tablicy dla kazdego procesu: "<<nRank<<endl;

      MPI_Bcast(&nRank, 1, MPI_INT, 0, MPI_COMM_WORLD);

      for(int i=1;i<size;i++)
      {
    MPI_Send(&tab[i*nRank], 25, MPI_INT, i, 50, MPI_COMM_WORLD);
      }

        maxRank = tab[0];
     for (int i = 1;i<nRank;++i)
      {
    if(maxRank < tab[i])
    {
      maxRank = tab[i];
    }
      }
      cout<<"RANK" << rank<< ", Max z tablicy = "<<maxRank<<endl;



     cout<<"Max all = "<<maxAll<<endl;
      delete[] tab;
    }
    else        //każdy inny
    {
     MPI_Bcast(&nRank, 1, MPI_INT, 0, MPI_COMM_WORLD);
     cout<<"Rank = "<<rank<<", tablica o rozmiarze: "<<nRank<<endl;
     int * tab = new int[nRank];
     MPI_Recv(tab, 25, MPI_INT, 0, 50, MPI_COMM_WORLD, MPI_STATUS_IGNORE);

     maxRank = tab[0];
     for (int i = 1;i<nRank;++i)
      {
    if(maxRank < tab[i])
    {
      maxRank = tab[i];
    }
      }

     cout<<"RANK" << rank<< ", Max z tablicy = "<<maxRank<<endl;

    MPI_Reduce(&maxRank, &maxAll, 1, MPI_INT, MPI_MAX, 0, MPI_COMM_WORLD);
     delete [] tab;

    }



  MPI_Finalize();
  return 0;
}