std::div, std::ldiv, std::lldiv, std::imaxdiv
cppreference.com
<tbody>
</tbody>
std::div_t div( int x, int y ); |
(1) | (constexpr C++23) |
std::ldiv_t div( long x, long y ); |
(2) | (constexpr C++23) |
std::lldiv_t div( long long x, long long y ); |
(3) | ( C++11) (constexpr C++23) |
std::ldiv_t ldiv( long x, long y ); |
(4) | (constexpr C++23) |
std::lldiv_t lldiv( long long x, long long y ); |
(5) | ( C++11) (constexpr C++23) |
std::imaxdiv_t div( std::intmax_t x, std::intmax_t y ); |
(6) | ( C++11) (constexpr C++23) |
std::imaxdiv_t imaxdiv( std::intmax_t x, std::intmax_t y ); |
(7) | ( C++11) (constexpr C++23) |
x y.
| ( C++11) |
|
, ( ). |
( C++11) |
|
|
( C++11) |
| x, y |
, (int, long, long long, std::intmax_t ), std::div_t, std::ldiv_t, std::lldiv_t, std::imaxdiv_t, :
std::div_t
struct div_t { int quot; int rem; };
struct div_t { int rem; int quot; };
std::ldiv_t
struct ldiv_t { long quot; long rem; };
struct ldiv_t { long rem; long quot; };
std::lldiv_t
struct lldiv_t { long long quot; long long rem; };
struct lldiv_t { long long rem; long long quot; };
std::imaxdiv_t
struct imaxdiv_t { std::intmax_t quot; std::intmax_t rem; };
struct imaxdiv_t { std::intmax_t rem; std::intmax_t quot; };
, .
C++11 , , std::div .
, , , / %, .
#include <cassert>
#include <cmath>
#include <cstdlib>
#include <iostream>
#include <sstream>
#include <string>
std::string division_with_remainder_string(int dividend, int divisor)
{
auto dv = std::div(dividend, divisor);
assert(dividend == divisor * dv.quot + dv.rem);
assert(dv.quot == dividend / divisor);
assert(dv.rem == dividend % divisor);
auto sign = [](int n){ return n > 0 ? 1 : n < 0 ? -1 : 0; };
assert((dv.rem == 0) or (sign(dv.rem) == sign(dividend)));
return (std::ostringstream() << std::showpos << dividend << " = "
<< divisor << " * (" << dv.quot << ") "
<< std::showpos << dv.rem).str();
}
std::string itoa(int n, int radix /*[2..16]*/)
{
std::string buf;
std::div_t dv{}; dv.quot = n;
do
{
dv = std::div(dv.quot, radix);
buf += "0123456789abcdef"[std::abs(dv.rem)]; //
}
while(dv.quot);
if (n < 0)
buf += '-';
return {buf.rbegin(), buf.rend()};
}
int main()
{
std::cout << division_with_remainder_string(369, 10) << '\n'
<< division_with_remainder_string(369, -10) << '\n'
<< division_with_remainder_string(-369, 10) << '\n'
<< division_with_remainder_string(-369, -10) << "\n\n";
std::cout << itoa(12345, 10) << '\n'
<< itoa(-12345, 10) << '\n'
<< itoa(42, 2) << '\n'
<< itoa(65535, 16) << '\n';
}
:
+369 = +10 * (+36) +9
+369 = -10 * (-36) +9
-369 = +10 * (-36) -9
-369 = -10 * (+36) -9
12345
-12345
101010
ffff
(C++11)(C++11) |
() |
(C++11)(C++11)(C++11) |
() |
(C++11)(C++11)(C++11) |
, () |
C div
| |
| 1. | . |
| 2. | ( ) . |