C Programming Practice - Page 4

#include <stdio.h> /* printf */

/* Swap the contents of two pointers. Do not modify the prototype.
   Use your function from PointerPractice_3 here. */
void SwapInts(int *a,int *b )
{
  /* Place your code here. Modify these lines. */
  int temp = *a;
  *a = *b;
  *b = temp;
}

/* Print contents of an array. Do not modify this function. */
void PrintArray( const int* array, const int size )
{
  int i;
  for(i = 0; i < size; ++i, ++array)
  {
    if(i != size - 1)
      printf( "%d, ", *array);
    else
      printf( "%d\n", *array);
  }
}

int main( void )
{
  /* Create array on the stack. */
  int stackArray[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

  /* Get size of array. stackArray can be treated as pointer to first element. */
  int arraySize = sizeof( stackArray ) / sizeof( *stackArray );

  /* Can treat name of an array as pointer to first element. */
  PrintArray( stackArray, arraySize );

  /* Reverse the array here */
  /**/
  /**/
  /**/
  int i, j;
  for (i = (arraySize - 1); i > 0; i--)
  {
    for (j = 1; j <= i; j++)
    {
      if (stackArray[j-1] < stackArray[j])
      {
        SwapInts(&stackArray[j-1], &stackArray[j]);
      }
    }
  }

  PrintArray( stackArray, arraySize );

  /* Correct output:
     0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
     10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 */

  return 0;
}