/*
================================================================
 example: use of the random number generator - rand
 from standard C++ library
 the code generates 
 a) integer random numbers between i1 and i2
 b) double random numbers between 0.0 and 1.0
 AG 
================================================================
*/
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cstdlib>
#include <cmath>
#include <ctime>
using namespace std;

int main ()
{
  int nmax = 10, i;    /* define how many random numbers to generate */
  int i1 = 1, i2 = 6; /* define interval of integer random numbers [i1 - i2] */
  int irandom;
  double drandom;
  
  cout.precision(4);
  cout.setf(ios::fixed | ios::showpoint); 
  
/* for writing random numbers to a file */
 ofstream file_1;
 file_1.open ("table01.dat");
 file_1.precision(5);
 file_1.setf(ios::fixed | ios::showpoint);
 ofstream file_2;
 file_2.open ("table02.dat");
 file_2.precision(5);
 file_2.setf(ios::fixed | ios::showpoint);   

/* Part 1: integer random numbers*/
  cout << "integer random numbers between "<< i1<<" and "<< i2 << endl;
  srand (222);        /* initial seed with some number */
//  srand(time(NULL)); /* call time if you want to "randomize" the seed value */
  for (i=0; i < nmax; i=i+1)
  {
/* random number between i1 and i2 */
      irandom = rand()%(i2-i1+1)+i1; /*number between i1 & i2*/
/* another method to generate a random number between i1 & i2*/
//    irandom = i1 + int(1.0*(i2-i1+1)*rand()/(RAND_MAX-1.0)); 
      cout << "i = " << irandom << endl;
      file_1  << setw(3) << irandom << endl; /* output to a file */
  }
    cout << "The value of RAND_MAX is " <<  RAND_MAX << endl;

/* Part 2: double float random numbers*/ 
  cout << endl << "real random numbers between 0.0 and 1.0" << endl; 
//  srand(time(NULL));
  for (i=0; i < nmax; i=i+1)
  {
      drandom = 1.0*rand()/(RAND_MAX-1.0);  /* random number between 0.0 and 1.0 */
      cout << "d = " << drandom << endl;
      file_2  << " " << drandom << endl;   /* output to a file */
  }
  return 0;
}