#include <iostream.h>

// Read this program and think about what will
//   be printed. Then compile this program with 
//   your favorite compiler, and explain the results.

// For the latest version of Borland C++ you may need to
//   add  using namespace std;  here.
// You also may need to change (unsigned) to (unsigned int) .

// This code can be found at
//   http://www.ccs.neu.edu/home/sbratus/com1101/   

int main(){
 
  double x = 43.0;
  double y = 57.0;
  double z;

  double * p;   // pointers to double
  double * q;
  double * r;

  p = &x;
  q = &y;
  r = &z;

  // (unsigned) before the pointer name makes the pointer print as 
  // an unsigned positive integer

  cout << "p = " << (unsigned) p << endl; 
  cout << "q = " << (unsigned) q << endl;

  *r = *p;
  *p = *q;
  *q = *r;

  cout << "x = " << x << endl; 
  cout << "y = " << y << endl << endl; 
 
  //---------------------------------------------------

  int i;
  int * p1;

  p1 = &i;

  cout << "p1 = " << (unsigned) p1 << endl;
  p1 = p1 + 1;
  cout << "p1 = " << (unsigned) p1 << endl;
  cout << "size of int = " << sizeof(int) << endl << endl;

  double t;
  double * p2;

  p2 = &t;
  cout << "p2 = " << (unsigned) p2 << endl;
  p2 = p2 + 1;
  cout << "p2 = " << (unsigned) p2 << endl;
  cout << "size of double = " << sizeof(double) << endl << endl;

  char ch;
  char * p3;

  p3 = &ch;
   
  cout << "p3 = " << (unsigned) p3 << endl;
  p3 = p3 + 1;
  cout << "p3 = " << (unsigned) p3 << endl;
  cout << "size of char = " << sizeof(char) << endl << endl;

  //---------------------------------------------------

  int a[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
  int * ptr;

  ptr = a;

  for( int k=0; k<10; k++ ){
    cout << *ptr << " ";
    ptr++;
  }
  cout << endl;

  ptr = a;
  for( int j=0; j<10; j++ ){
    *ptr = -( *ptr );
    ptr++;
  }

  for( int l=0; l<10; l++ )
    cout << a[l] << " ";
  cout << endl;

  ptr = &( a[5] );
  *ptr = 100;

  for( int l=0; l<10; l++ )
    cout << a[l] << " ";
  cout << endl;

}