//pointersort.cpp
//sorting by moving pointers, not the data
#include<iostream> //cout, endl
using namespace std;

const int MAX = 10;

void swap(int* &p, int* &q)
// swaps addresses stored in p and q
  {int* temp;
  temp = p;
  p = q;
  q = temp;
  return;
  } //end swap

void bubblesort(int* list[], int size)
//list is an array of pointers
//size is the number of items in list
  {int end=size-1;
  int i;
  for (end=size-1; end>=1; end--)
    for (i=0; i<=end-1; i++)
      if ( *list[i] > *list[i+1] )
        swap(list[i],list[i+1]);
  return;
  }  //  end bubblesort

int main()
  {
  int datalist[MAX]={100,37,26,48,2};
  int* pointerlist[MAX];
  int numitems=5;  //array can hold MAX, 
                   //only use numitems
  int j;
  for (j=0; j<MAX; j++)
    pointerlist[j]=0;  //to be safe

  //have the pointers point to the data
  //match pointers with data
  int i;
  for (i=0; i<numitems; i++)
    pointerlist[i]=&datalist[i];

  bubblesort(pointerlist,numitems);

  cout << "The ordered list as revealed " 
    << "with pointerlist:" 
       << endl;
  for (i=0; i<numitems; i++)
    cout << *pointerlist[i] << ' ';
  cout << "\nThe list as it is still stored" 
    << " in datalist:" 
       << endl;
  for (i=0; i<numitems; i++)
    cout << datalist[i] << ' ';
  return 0;
  }  //end main