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<h1 id="firstHeading" class="firstHeading">div, ldiv, lldiv, imaxdiv</h1> <table class="t-dcl-begin"> <tr class="t-dsc-header"> <th> Defined in header <code><stdlib.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl"> <td> <pre data-language="c">div_t div( int x, int y );</pre>
</td> <td> (1) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl"> <td> <pre data-language="c">ldiv_t ldiv( long x, long y );</pre>
</td> <td> (2) </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">lldiv_t lldiv( long long x, long long y );</pre>
</td> <td> (3) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> <tr class="t-dsc-header"> <th> Defined in header <code><inttypes.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl t-since-c99"> <td> <pre data-language="c">imaxdiv_t imaxdiv( intmax_t x, intmax_t y );</pre>
</td> <td> (4) </td> <td> <span class="t-mark-rev t-since-c99">(since C99)</span> </td> </tr> </table> <p>Computes both the quotient and the remainder of the division of the numerator <code>x</code> by the denominator <code>y</code>.</p>
<table class="t-rev-begin"> <tr class="t-rev t-until-c99">
<td> <p>Computes quotient and remainder simultaneously. The quotient is the algebraic quotient with any fractional part discarded (truncated towards zero). The remainder is such that <code>quot * y + rem == x</code>.</p>
</td> <td><span class="t-mark-rev t-until-c99">(until C99)</span></td>
</tr> <tr class="t-rev t-since-c99">
<td> <p>Computes the quotient (the result of the expression <code>x / y</code>) and remainder (the result of the expression <code>x % y</code>) simultaneously.</p>
</td> <td><span class="t-mark-rev t-since-c99">(since C99)</span></td>
</tr> </table> <h3 id="Parameters"> Parameters</h3> <table class="t-par-begin"> <tr class="t-par"> <td> x, y </td> <td> - </td> <td> integer values </td>
</tr>
</table> <h3 id="Return_value"> Return value</h3> <p>If both the remainder and the quotient can be represented as objects of the corresponding type (<code>int</code>, <code>long</code>, <code>long long</code>, <code><a href="http://en.cppreference.com/w/c/types/integer"><span class="kw118">intmax_t</span></a></code>, respectively), returns both as an object of type <code>div_t</code>, <code>ldiv_t</code>, <code>lldiv_t</code>, <code>imaxdiv_t</code> defined as follows:</p>
<div class="t-member"> <h2 id="div_t"> div_t</h2> <div class="c source-c"><pre data-language="c">struct div_t { int quot; int rem; };</pre></div> <p>or</p>
<div class="c source-c"><pre data-language="c">struct div_t { int rem; int quot; };</pre></div> </div> <div class="t-member"> <h2 id="ldiv_t"> ldiv_t</h2> <div class="c source-c"><pre data-language="c">struct ldiv_t { long quot; long rem; };</pre></div> <p>or</p>
<div class="c source-c"><pre data-language="c">struct ldiv_t { long rem; long quot; };</pre></div> </div> <div class="t-member"> <h2 id="lldiv_t"> lldiv_t</h2> <div class="c source-c"><pre data-language="c">struct lldiv_t { long long quot; long long rem; };</pre></div> <p>or</p>
<div class="c source-c"><pre data-language="c">struct lldiv_t { long long rem; long long quot; };</pre></div> </div> <div class="t-member"> <h2 id="imaxdiv_t"> imaxdiv_t</h2> <div class="c source-c"><pre data-language="c">struct imaxdiv_t { intmax_t quot; intmax_t rem; };</pre></div> <p>or</p>
<div class="c source-c"><pre data-language="c">struct imaxdiv_t { intmax_t rem; intmax_t quot; };</pre></div> </div> <p>If either the remainder or the quotient cannot be represented, the behavior is undefined.</p>
<h3 id="Notes"> Notes</h3> <p>Until C99, 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 <code>div</code> and <code>ldiv</code>.</p>
<p>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 <code>/</code> and <code>%</code> where suitable.</p>
<h3 id="Example"> Example</h3> <div class="t-example"> <div class="c source-c"><pre data-language="c">#include <assert.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
void reverse(char* first, char* last)
{
for (--last; first < last; ++first, --last)
{
char c = *last;
*last = *first;
*first = c;
}
}
// returns empty buffer in case of buffer overflow
char* itoa(int n, int base, char* buf, size_t buf_size)
{
assert(2 <= base && base <= 16 && buf && buf_size);
div_t dv = {.quot = n};
char* p = buf;
do
{
if (!--buf_size)
return (*buf = '\0'), buf;
dv = div(dv.quot, base);
*p++ = "0123456789abcdef"[abs(dv.rem)];
}
while(dv.quot);
if (n < 0)
*p++ = '-';
*p = '\0';
reverse(buf, p);
return buf;
}
int main(void)
{
char buf[16];
printf("%s\n", itoa(0, 2, buf, sizeof buf));
printf("%s\n", itoa(007, 3, buf, sizeof buf));
printf("%s\n", itoa(12346, 10, buf, sizeof buf));
printf("%s\n", itoa(-12346, 10, buf, sizeof buf));
printf("%s\n", itoa(-42, 2, buf, sizeof buf));
printf("%s\n", itoa(INT_MAX, 16, buf, sizeof buf));
printf("%s\n", itoa(INT_MIN, 16, buf, sizeof buf));
}</pre></div> <p>Possible output:</p>
<div class="text source-text"><pre data-language="c">0
21
12346
-12346
-101010
7fffffff
-80000000</pre></div> </div> <h3 id="References"> References</h3> <ul>
<li> C23 standard (ISO/IEC 9899:2023): </li>
<ul>
<li> 7.8.2.2 The imaxdiv function (p: TBD) </li>
<li> 7.22.6.2 The div, ldiv and lldiv functions (p: TBD) </li>
</ul>
<li> C17 standard (ISO/IEC 9899:2018): </li>
<ul>
<li> 7.8.2.2 The imaxdiv function (p: 159) </li>
<li> 7.22.6.2 The div, ldiv and lldiv functions (p: 259) </li>
</ul>
<li> C11 standard (ISO/IEC 9899:2011): </li>
<ul>
<li> 7.8.2.2 The imaxdiv function (p: 219) </li>
<li> 7.22.6.2 The div, ldiv and lldiv functions (p: 356) </li>
</ul>
<li> C99 standard (ISO/IEC 9899:1999): </li>
<ul>
<li> 7.8.2.2 The imaxdiv function (p: 200) </li>
<li> 7.20.6.2 The div, ldiv and lldiv functions (p: 320) </li>
</ul>
<li> C89/C90 standard (ISO/IEC 9899:1990): </li>
<ul>
<li> 4.10 div_t, ldiv_t </li>
<li> 4.10.6.2 The div function </li>
<li> 4.10.6.4 The ldiv function </li>
</ul>
</ul> <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td> <div><a href="fmod" title="c/numeric/math/fmod"> <span class="t-lines"><span>fmod</span><span>fmodf</span><span>fmodl</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div> </td> <td> computes remainder of the floating-point division operation <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td> <div><a href="remainder" title="c/numeric/math/remainder"> <span class="t-lines"><span>remainder</span><span>remainderf</span><span>remainderl</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div> </td> <td> computes signed remainder of the floating-point division operation <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td> <div><a href="remquo" title="c/numeric/math/remquo"> <span class="t-lines"><span>remquo</span><span>remquof</span><span>remquol</span></span></a></div>
<div><span class="t-lines"><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span><span><span class="t-mark-rev t-since-c99">(C99)</span></span></span></div> </td> <td> computes signed remainder as well as the three last bits of the division operation <br> <span class="t-mark">(function)</span> </td>
</tr> <tr class="t-dsc"> <td colspan="2"> <span><a href="https://en.cppreference.com/w/cpp/numeric/math/div" title="cpp/numeric/math/div">C++ documentation</a></span> for <code>div</code> </td>
</tr> </table> <h3 id="External_links"> External links</h3> <table> <tr style="vertical-align:top;"> <td>1. </td> <td>
<a href="https://en.wikipedia.org/wiki/Euclidean_division" class="extiw" title="enwiki:Euclidean division">Euclidean division</a> — From Wikipedia. </td>
</tr> <tr style="vertical-align:top;"> <td>2. </td> <td>
<a href="https://en.wikipedia.org/wiki/Modulo" class="extiw" title="enwiki:Modulo">Modulo (and Truncated division)</a> — From Wikipedia. </td>
</tr>
</table> <div class="_attribution">
<p class="_attribution-p">
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<a href="https://en.cppreference.com/w/c/numeric/math/div" class="_attribution-link">https://en.cppreference.com/w/c/numeric/math/div</a>
</p>
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