/C++

# std::div, std::ldiv, std::lldiv

Defined in header `<cstdlib>`
`std::div_t     div( int x, int y );`
(1)
`std::ldiv_t    div( long x, long y );`
(2)
`std::lldiv_t   div( long long x, long long y );`
(3) (since C++11)
`std::ldiv_t   ldiv( long x, long y );`
(4)
`std::lldiv_t lldiv( long long x, long long y );`
(5) (since C++11)
Defined in header `<cinttypes>`
`std::imaxdiv_t div( std::intmax_t x, std::intmax_t y );`
(6) (since C++11)
`std::imaxdiv_t imaxdiv( std::intmax_t x, std::intmax_t y );`
(7) (since C++11)

Computes both the quotient and the remainder of the division of the numerator `x` by the denominator `y`.

 The quotient is the algebraic quotient with any fractional part discarded (truncated towards zero). The remainder is such that `quot * y + rem == x`. (until C++11) The quotient is the result of the expression `x/y`. The remainder is the result of the expression `x%y`. (since C++11)

### Parameters

 x, y - integer values

### Return value

If both the remainder and the quotient can be represented as objects of the corresponding type (int, long, long long, std::imaxdiv_t, respectively), returns both as an object of type `std::div_t`, `std::ldiv_t`, `std::lldiv_t`, `std::imaxdiv_t` defined as follows:

## std::div_t

`struct div_t { int quot; int rem; };`

or.

`struct div_t { int rem; int quot; };`

## std::ldiv_t

`struct ldiv_t { long quot; long rem; };`

or.

`struct ldiv_t { long rem; long quot; };`

## std::lldiv_t

`struct lldiv_t { long long quot; long long rem; };`

or.

`struct lldiv_t { long long rem; long long quot; };`

## std::imaxdiv_t

`struct imaxdiv_t { std::intmax_t quot; std::intmax_t rem; };`

or.

`struct imaxdiv_t { std::intmax_t rem; std::intmax_t quot; };`

If either the remainder or the quotient cannot be represented, the behavior is undefined.

### Notes

Until C++11, the rounding direction of the quotient and the sign of the remainder in the built-in division and remainder operators was implementation-defined if either of the operands was negative, but it was well-defined in `std::div`.

On many platforms, a single CPU instruction obtains both the quotient and the remainder, and this function may leverage that, although compilers are generally able to merge nearby / and % where suitable.

### Example

```#include <string>
#include <cmath>
#include <cstdlib>
#include <iostream>

std::string itoa(int n, int base)
{
std::string buf;
std::div_t dv{}; dv.quot = n;
do {
dv = std::div(dv.quot, base);
buf += "0123456789abcdef"[std::abs(dv.rem)];  // string literals are arrays
} while(dv.quot);
if(n<0) buf += '-';
return {buf.rbegin(), buf.rend()};
}

int main()
{
std::cout << itoa(12345, 10) << '\n'
<< itoa(-12345, 10) << '\n'
<< itoa(65535, 16) << '\n';
}```

Output:

```12345
-12345
ffff```