// ==================================================================
// Author: Jean-Michel Richer
// Date: Aug 2020
// Last modified: November 2020
// Purpose: Use of MPI::BCast
// The master process creates its own local data and they are send
// to other processes (that have a rank not equal to the master)
// ==================================================================
#include <unistd.h>
#include <unistd.h>  // for sleep

#include <cstdlib>
#include <iostream>
#include <numeric>
using namespace std;
#include "ezmpi.hpp"
using namespace ez::mpi;

/**
 * run master and slaves
 */
void run(int argc, char* argv[]) {
    Process process(argc, argv);

    // declare a vector of vec_size integers
    int vec_size = 10;
    vector<int> vec(vec_size, 0);

    if (process.is_master()) {
        // master process will:
        // 1- fille the vector
        // 2- send the vector to other processes (see broadcast below)
        iota(vec.begin(), vec.end(), 1);

        process << "- create global array =" << vec << endl;
    }

    // the master process sends the vector to all other processes
    // the instruction must be executed by all other processes
    process.broadcast(vec);

    // Each process reports the data it has received
    if (process.id() != MASTER) {
        process << "- local copy array=" << vec << endl;
    }

    process.logs(cout);
}

// ==================================================================
// C++ version
// ==================================================================
int main(int argc, char** argv) {
    // call a function that contains the code for the master and
    // the slaves in order to avoid problems of initialization and
    // finalization of processes
    run(argc, argv);

    exit(EXIT_SUCCESS);
}