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20.2 Integer Division

This section describes functions for performing integer division. These functions are redundant when GNU CC is used, because in GNU C the ‘/’ operator always rounds towards zero. But in other C implementations, ‘/’ may round differently with negative arguments. div and ldiv are useful because they specify how to round the quotient: towards zero. The remainder has the same sign as the numerator.

These functions are specified to return a result r such that the value r.quot*denominator + r.rem equals numerator.

To use these facilities, you should include the header file stdlib.h in your program.

— Data Type: div_t

This is a structure type used to hold the result returned by the div function. It has the following members:

int quot
The quotient from the division.
int rem
The remainder from the division.

— Function: div_t div (int numerator, int denominator)

This function div computes the quotient and remainder from the division of numerator by denominator, returning the result in a structure of type div_t.

If the result cannot be represented (as in a division by zero), the behavior is undefined.

Here is an example, albeit not a very useful one. 

          div_t result;
          result = div (20, -6);

Now result.quot is -3 and result.rem is 2.

— Data Type: ldiv_t

This is a structure type used to hold the result returned by the ldiv function. It has the following members:

long int quot
The quotient from the division.
long int rem
The remainder from the division.

(This is identical to div_t except that the components are of type long int rather than int.)

— Function: ldiv_t ldiv (long int numerator, long int denominator)

The ldiv function is similar to div, except that the arguments are of type long int and the result is returned as a structure of type ldiv_t.

— Data Type: lldiv_t

This is a structure type used to hold the result returned by the lldiv function. It has the following members:

long long int quot
The quotient from the division.
long long int rem
The remainder from the division.

(This is identical to div_t except that the components are of type long long int rather than int.)

— Function: lldiv_t lldiv (long long int numerator, long long int denominator)

The lldiv function is like the div function, but the arguments are of type long long int and the result is returned as a structure of type lldiv_t.

The lldiv function was added in ISO C99.

— Data Type: imaxdiv_t

This is a structure type used to hold the result returned by the imaxdiv function. It has the following members:

intmax_t quot
The quotient from the division.
intmax_t rem
The remainder from the division.

(This is identical to div_t except that the components are of type intmax_t rather than int.)

See Integers for a description of the intmax_t type.

— Function: imaxdiv_t imaxdiv (intmax_t numerator, intmax_t denominator)

The imaxdiv function is like the div function, but the arguments are of type intmax_t and the result is returned as a structure of type imaxdiv_t.

See Integers for a description of the intmax_t type.

The imaxdiv function was added in ISO C99.