/*
 * Various exercises with pointers, arrays, and dynamic allocation
 * (meant to illustrate language issues; not necessarily anything that
 *  would be directly useful in your own code; but if you can trace and
 *  understand this you're doing great!)
 * CSE303 demo program au07
 */


#include <stdio.h>
#include <stdlib.h>

void swap(void** p1, void** p2) {
  void* tmp = *p1;
  *p1 = *p2;
  *p2 = tmp;
}

void client() {
  int* ip1 = (int*)malloc(sizeof(int));
  *ip1 = 17;
  int* ip2 = (int*)calloc(1,sizeof(int));
  swap((void**)&ip1,(void**)&ip2);

  int* ipArray = (int*)malloc(*ip2 * sizeof(int)); // size 17 array
  int i;
  for(i=0; i < *ip2; ++i)
    ipArray[i]=i;

  // technically WRONG (int and void* not necessary the same size)
  // but works on attu and many other systems where ints and pointers
  // are both 32 bits
  swap((void**)&ipArray[3],(void**)ipArray+9); // two ways to pointing elements
  
  printf("%d %d\n",*ip1,*ip2);
  for(i=0; i < *ip2; ++i)
    printf("%d ", ipArray[i]);
  printf("\n");
  
  // a way to _kind of_ check that the WRONG thing we did will probably work
  if(sizeof(int) != sizeof(void*))
    fprintf(stderr,"uh-oh!");
}

int main(int argc, char**argv) {
  client();
  return 0;
}