// MPI_FIRST.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <mpi.h>
#include <string>
//#include <unistd.h>
#include <stdlib.h>

using namespace std;

void init(int * tab, int n)
{
    for (int i = 10; i>n; i--)
    {
        tab[i] = i;
    }
}

int min(const int& a, const int& b)
{
    return (a<b) ? a : b;
}

int findMIN(const int* tmptab, const int n)
{
    int mn = tmptab[0];

    for (int i = 1; i<n; ++i)
    {
        mn = min(mn, tmptab[i]);
    }

    return mn;
}

int main(int argc, char** argt)
{
    int rank, size;
    MPI_Init(&argc, &argt);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    MPI_Comm_size(MPI_COMM_WORLD, &size);

    int min;
    int *tab;
    int *tmptab;
    int nPart = -1;
    int n;

    if (rank == 0)
    {
        n = 10;
        nPart = n / size;
        tab = new int[n];
        init(tab, n);
    }
    MPI_Bcast(&nPart, 1, MPI_INT, 0, MPI_COMM_WORLD);
    tmptab = new int[nPart];
    MPI_Scatter(tab, nPart, MPI_INT, tmptab, nPart, MPI_INT, 0, MPI_COMM_WORLD);

    int local_MIN = findMIN(tmptab, nPart);

    MPI_Reduce(&local_MIN, &min, 1, MPI_INT, MPI_MIN, 0, MPI_COMM_WORLD);

    delete[] tab;
    delete[] tmptab;
    if (rank == 0)
    {
        cout << "Min to: " << min << endl;
    }
    MPI_Finalize();
    return 0;
}