#include <stdlib.h>		// has abs()

// Find sign (plus or minus) of integer.  (Used by divide_and_round().)
// Pre:  None.
// Post:  Return value is 1 if x >= 0, -1 otherwise.
int sign(int x)
{
  if (x >= 0) return 1;
  else return -1;
}

// Divide integers with rounding.
// Pre:  "divisor" is not zero.
// Post:  Return value is "dividend" divided by "divisor",
//     rounded to the nearest integer.
int divide_and_round(int dividend, int divisor)
{
  // To avoid any confusion about what "%" means for negative
  // numbers, we will work with absolute values and then
  // restore the proper sign at the end.

  // Compute quotient, remainder of abs(dividend) / abs(divisor).
  int Q = abs(dividend) / abs(divisor);
  int R = abs(dividend) % abs(divisor);

  // Compute absolute value of result:  Add one to quotient if
  // remainder is at least half of divisor.
  int abs_result;
  if ((2 * R) >= divisor)
    abs_result = Q + 1;
  else
    abs_result = Q;

  // Return result with proper sign.
  if (sign(dividend) == sign(divisor))
    return abs_result;
  else
    return -abs_result;
}