#include <boost/thread.hpp>
#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

double *a;
int rows;
int cols;
int nthreads;

void worker(int tid){
	for(int i=tid; i<rows; i+=nthreads){
		for(int j=0; j<cols; j++){
			a[i*cols+j]=(double) rand()/(RAND_MAX*1.0); 
	}
}
}
int main() {
	srand(time(0));
	rows=10;
	cols=10;

	nthreads=10;
	a=new double[rows*cols];
	boost::thread_group tg;
	for(int t=0; t<nthreads; t++)
		tg.create_thread(boost::bind(worker,t));
	tg.join_all();
	for(int i=0; i<rows; i++) {
		for(int j=0; j<cols; j++) {
			cout << a[i*cols+j] << " ";
			}
		cout << endl;
	}
}