C38 Answer

/* Puzzle C38 -- shift array elements N positions left; */
/*               the last N elements get 0;         */
/*               the first N elements are discarded */

void shiftLeftNArray( int arr[], int size, int shift )
{
  int j;
  
  if ( shift<0 ) return;
  if ( shift>=size )
  { 
    for ( j=0; j<size; j++ )
      arr[j] = 0;
    return;
  }
    
  for ( j=0; j<size-shift; j++ )
    arr[j] = arr[j+shift];
    
  for ( j=size-shift; j<size; j++ )
    arr[j] = 0;      
}