#include <iostream>
#include <chrono>
#include <cmath>
#include <unistd.h>

using namespace std;
using namespace std::chrono;

int main(int argc, char * argv[]) {

    int i,j;
    bool print = false;
  
    high_resolution_clock::time_point startTime, endTime;

    startTime = chrono::high_resolution_clock::now();


    if (argc > 1) {
       print = true;
    }


    for(i=1;i<1000000;i++) {
        if (print) cout << "factoring " << i << " ";
        for(j=1;j<sqrt(i) ;j++) {
	   if (i%j == 0) {
	      if (print) cout << j << " " << i/j << " " ;
	   }
	}
	if (print) cout << endl;
    }

    endTime = chrono::high_resolution_clock::now();

    cout << duration_cast<nanoseconds> (endTime-startTime).count() 
         << " nanoseconds" << endl;
    cout << duration_cast<microseconds> (endTime-startTime).count()
         << " microseconds" << endl;
    cout << duration_cast<milliseconds> (endTime-startTime).count()
         << " milliseconds" << endl;
    cout << duration_cast<seconds> (endTime-startTime).count() 
         << " seconds" << endl;

    return 0;
}