積算のオーバーフロー判定 (Math/is_multiplication_overflow.hpp)

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Last update: 2024-09-30 15:01:43+09:00
Include: #include "Math/is_multiplication_overflow.hpp"

is_multiplication_overflow

bool is_multiplication_overflow(long long a, long long b, long long limit)

$a \times b$が $limit$ を超えるかどうかを判定します。

計算量

$O(1)$

Verified with

test/Math/is_multiplication_overflow/abc169-b.test.cpp

Code

bool is_multiplication_overflow(long long a, long long b, long long limit)
{
    return a == 0 ? false : (limit / a) < b;
}

#line 1 "Math/is_multiplication_overflow.hpp"
bool is_multiplication_overflow(long long a, long long b, long long limit)
{
    return a == 0 ? false : (limit / a) < b;
}