Integer division ($\lfloor \frac{a}{b} \rfloor \lceil \frac{a}{b} \rceil$)
(library/math/integer-div.hpp)

• View this file on GitHub
• Last update: 2023-04-03 13:30:29+08:00
• Include: #include "library/math/integer-div.hpp"

floor_div(a, b) 回傳最大且 $\leq \frac{a}{b}$ 的整數

ceil_div(a, b) 回傳最小且 $\geq \frac{a}{b}$ 的整數

使用方法

int x, y;

int a = floor_div(x, y);
int b = ceil_div(x, y);
int c = floor_div(-2, 4); // -1
int d = floor_div(-5, 2); // -3
int e = ceil_div(-2, 4);  //  0

Required by

• library/data-structure/line-container.hpp

Verified with

• test/data-structure/line-container/yosupo-Line-Add-Get-Min.test.cpp
• test/math/integer-div/unit-test-integer-div.test.cpp

Code

#pragma once

namespace felix {

template<class T>
T floor_div(T a, T b) {
	return a / b - ((a ^ b) < 0 && a % b != 0);
}

template<class T>
T ceil_div(T a, T b) {
	return a / b + ((a ^ b) > 0 && a % b != 0);
}

} // namespace felix

#line 2 "library/math/integer-div.hpp"

namespace felix {

template<class T>
T floor_div(T a, T b) {
	return a / b - ((a ^ b) < 0 && a % b != 0);
}

template<class T>
T ceil_div(T a, T b) {
	return a / b + ((a ^ b) > 0 && a % b != 0);
}

} // namespace felix

Back to top page