/*
 **************************************************************************
 * Program name : 053_Function_and_pointer (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 : 2000/07/01 - first version                              *
 **************************************************************************
 * Description  : (a) Input an integer number (0-5)                       *
 *                (b) Output an error message                             *
 *                (c) Output the memory address and elements of Values    *
 *                (d) Try again ?                                         *
 **************************************************************************
*/
#include <iostream.h>
#include <stdlib.h>

void Function_Input(int [], const int);
void Function_Min_and_Max(int [], const int);
void Function_Bubblesort(int [], const int);

int main()
{
 // part 1 : declaration
 const int element = 6;
 int   Number[element];
 char  Again;

 do {
     // part 2 : Use different method to call function
     Function_Input(Number,element);
     Function_Min_and_Max(Number,element);
     Function_Bubblesort(Number,element);

     // part 3 : try another number ?
     cout << "\n\n\tTry another number (Y/N) : ";
     cin  >> Again;
     cout << "\n";
    } while (Again=='Y' || Again=='y');
 cout << "\n" << endl;

 system("PAUSE");
 return 0;
}

void Function_Input(int Number[], const int element)                 // Note (1)
{
 int Index;

 cout << "\nPart (1) : Call by reference with reference arguments\n";
 for (Index=0; Index<element; Index++)
   {
    cout << "\n\tPlease input the [" << Index+1 << "] integer : ";
    cin  >> Number[Index];
   }
 cout << "\n\n\tThe numbers are : ";
 for (Index=0; Index<element; Index++)
   cout << Number[Index] << "   ";
 cout << "\n\nEnd of Function_Input\n\n";
 system("PAUSE");
}

void Function_Min_and_Max(int *Num, const int element)               // Note (1)
{
 int Min, Max, Index;

 cout << "\nPart (2) : Call by reference with pointer argument - example 1\n";
 Min = *Num;
 Max = *Num;
 for (Index=0; Index<element; Index++)
   {
    if (Num[Index] < Min) Min = Num[Index];
    if (Num[Index] > Max) Max = Num[Index];
   }
 cout << "\n\tThe minimum number in the list is : " << Min
      << "\n\tThe maximum number in the list is : " << Max;
 cout << "\n\nEnd of Function_Min_and_Max\n\n";
 system("PAUSE");
}

void Function_Bubblesort(int *Num, const int element)          // Note (1) & (2)
{
 void swap(int *, int *);                                            // Note (3)

 int Index_1, Index_2, tempint;
 char swapYN;

 for (Index_1=1; Index_1<element; Index_1++)
   {
    swapYN = 'N';
    for (Index_2=0; Index_2<element-Index_1; Index_2++)
      if (Num[Index_2]>Num[Index_2+1])
        {
         swap(&Num[Index_2], &Num[Index_2+1]);
         swapYN = 'Y';
        }
    if (swapYN=='N') break;
   }
 cout << "\nPart (3) : Call by reference with pointer argument - example 2\n";
 cout << "\n\n\tAfter sorting, the numbers becomes : ";
 for (Index_1=0; Index_1<element; Index_1++)
 cout << Num[Index_1] << "   ";
 cout << "\n\nEnd of Function_Bubblesort\n\n";
 system("PAUSE");
}

void swap(int *elemeny_a, int *elemeny_b)
{
 int tempint = *elemeny_a;
 *elemeny_a = *elemeny_b;
 *elemeny_b = tempint;
}

/* Notes
   (1) There are there ways to pass arguments to a function -- call-by-value,
       call-by-reference with reference arguments and call-by-reference with
       pointer arguments. The return statement can be used in a function to
       return one value from a called function to a caller. If we want to
       modify the original values of the arguments, we must pass arguments to
       a function by call-by-reference with reference arguments or pointer
       arguments.

   (2) The function Function_Min_and_Max and Function_Bubblesort takes Num as
       an argument. The function receives the address (memory location) of the
       first element of the array as an argument, stores the address locally
       in variable Num.

   (3) The prototype for function swap is included in the body of function
       function_Bubblesort because it is the only function that calls swap.
*/