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sled/include/sled/numerics/divide_round.h
2024-03-23 08:53:11 +08:00

48 lines
1.4 KiB
C++

/**
* @file : divide_round
* @created : Saturday Feb 03, 2024 09:53:08 CST
* @license : MIT
**/
#ifndef SLED_NUMERICS_DIVIDE_ROUND_H
#define SLED_NUMERICS_DIVIDE_ROUND_H
#pragma once
#include <type_traits>
namespace sled {
template<typename Dividend, typename Divisor>
inline auto
DivideRoundUp(Dividend dividend, Divisor divisor) -> decltype(Dividend() / Divisor())
{
static_assert(std::is_integral<Dividend>(), "");
static_assert(std::is_integral<Divisor>(), "");
auto quotient = dividend / divisor;
auto remainder = dividend % divisor;
return quotient + (remainder > 0 ? 1 : 0);
}
template<typename Dividend, typename Divisor>
inline auto
DivideRoundToNearst(Dividend dividend, Divisor divisor) -> decltype(Dividend() / Divisor())
{
static_assert(std::is_integral<Dividend>(), "");
static_assert(std::is_integral<Divisor>(), "");
if (dividend < Dividend(0)) {
auto half_of_divisor = divisor / 2;
auto quotient = dividend / divisor;
auto remainder = dividend % divisor;
if (half_of_divisor < -remainder) { --quotient; }
return quotient;
}
auto half_of_divisor = (divisor - 1) / 2;
auto quotient = dividend / divisor;
auto remainder = dividend % divisor;
if (half_of_divisor < remainder) { ++quotient; }
return quotient;
}
}// namespace sled
#endif// SLED_NUMERICS_DIVIDE_ROUND_H