/*
 **************************************************************************
 * Program name : 031_Rounding (Version 1.00)                             *
 * Author       : Duck Wong                                               *
 * Language     : C / C++                                                 *
 * Compiler     : Boodshed Dec-C++ compiler Ver 3.95                      *
 * Computer     : PII350                                                  *
 * O/S          : Windows 98                                              *
 **************************************************************************
 * Version 1.00 : 2000/06/12 - first version                              *
 **************************************************************************
 * Description  : (a) Input a real number                                 *
 *                (b) Output the number in different format               *
 *                (c) Try again ?                                         *
 **************************************************************************
*/
#include <iostream.h>
#include <stdlib.h>
#include <math.h>
#include <iomanip.h>

int main()
{
 // part 1 : declaration
 double  Number, Div, Temp;
 int    Index;
 char   Again;

 do {
     // part 2 : Repeat asking a positive real number
     do {
         cout << "\nPlease enter a positive real number : ";
         cin  >> Number;
        } while (Number<=0);

     // part 3 : Calculation and output results
     cout << "\nThe inputted number can be round up to : ";
     for (Index=4 ; Index >= 1; Index--)                             // Note (1)
       {
        if (floor(Number / pow(10,Index-1)) != 0)
          cout << setprecision(0) << resetiosflags(ios::showpoint) << "\n" 
               << floor((Number+0.5*pow(10,Index-1)) / pow(10,Index-1))
                  *pow(10,Index-1);
       }
     for (Index=1 ; Index <= 10; Index++)                            // Note (2)
       cout << setprecision(Index)
            << setiosflags(ios::fixed |ios::showpoint)
            << "\n"
            << floor(floor(Number*pow(10,Index+1)+5)/10)/pow(10,Index);

     // part 4 : try another number ?
     cout << "\n\n\aTry another number (Y/N) : ";
     cin  >> Again;
     cout << "\n";
    } while (Again=='Y' || Again=='y');
 cout << "\n" << endl;

 system("PAUSE");
 return 0;
}

/* Notes
   (1) Round up to interger of Thousand, Hundred and Ten etc.
       (a)  The statement "setprecision(0)" set the ouput without decimal digit.
       (b)  The statement "resetiosflags(ios::showpoint)"  set the ouput without
            decimal point.

       (c)  Example : Let us say the inputted number is 456.5639
 ----------------------------------------------------------------------------
 Index                                   |      4 |      3 |      2 |      1
 ----------------------------------------------------------------------------
 pow(10,Index-1)                         |   1000 |    100 |     10 |      1
 ----------------------------------------------------------------------------
 Number+0.5*pow(10,Index-1)              | 956.XX | 506.XX | 461.XX | 457.XX
 ----------------------------------------------------------------------------
 floor((Number+0.5*pow(10,Index-1))      |        |        |        |
  / pow(10,Index-1))                     |      0 |      5 |     46 |    457
 ----------------------------------------------------------------------------
 floor((Number+0.5*pow(10,Index-1))      | 0*1000 |  5*100 |  46*10 |  457*1
  / pow(10,Index-1)) *pow(10,Index-1);   |    = 0 |  = 500 |  = 460 |  = 457
 ----------------------------------------------------------------------------

       The output is :
       ---------------------------
       500
       460
       457

   (2) Round up to nearest Ten, Hundred and Thousand etc of deciaml
       (a) The statement "setprecision(Index)" set the no. of decimal digits.
       (b) The statement "setiosflags(ios::fixed |ios::showpoint)" set the
           output format of float with decimal point and fixed number of
           decimal digits.
       (c) Example : Let us say the inputted number is 456.5639

       ----------------------
       Index   |  Output
       ----------------------
         1     |  456.6
         2     |  456.56
         3     |  456.564
         4     |  456.5639
         5     |  456.56390
       ----------------------
*/