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std::lcm(3)		       C++ Standard Libary		     std::lcm(3)

NAME
     std::lcm - std::lcm

Synopsis
	Defined in header <numeric>
	template< class M, class N >			     (since C++17)
	constexpr std::common_type_t<M, N> lcm( M m, N n );

	Computes the least common multiple of the integers m and n.

	If  either  M or N is not an integer type, or if either is (possibly cv-
     qualified)
	bool, the program is ill-formed.

	The behavior is undefined if |m|, |n|, or the least common  multiple  of
     |m| and |n|
	is not representable as a value of type std::common_type_t<M, N>.

Parameters
	m, n - integer values

Return value
	If  either  m  or  n is zero, returns zero. Otherwise, returns the least
     common multiple
	of |m| and |n|.

Exceptions
	Throws no exceptions.

Notes
	Feature-test macro  Value    Std	Feature
	__cpp_lib_gcd_lcm  201606L (C++17) std::gcd, std::lcm

Example
     // Run this code

      #include <iostream>
      #include <numeric>

      #define OUT(...) std::cout << #__VA_ARGS__ << " = " << __VA_ARGS__ << '\n'

      constexpr auto lcm(auto x, auto... xs)
      {
	  return ((x = std::lcm(x, xs)), ...);
      }

      int main()
      {
	  constexpr int p{2 * 2 * 3};
	  constexpr int q{2 * 3 * 3};
	  static_assert(2 * 2 * 3 * 3 == std::lcm(p, q));
	  static_assert(225 == std::lcm(45, 75));

	  static_assert(std::lcm( 6,  10) == 30);
	  static_assert(std::lcm( 6, -10) == 30);
	  static_assert(std::lcm(-6, -10) == 30);

	  static_assert(std::lcm( 24, 0) == 0);
	  static_assert(std::lcm(-24, 0) == 0);

	  OUT(lcm(2 * 3, 3 * 4, 4 * 5));
	  OUT(lcm(2 * 3 * 4, 3 * 4 * 5, 4 * 5 * 6));
	  OUT(lcm(2 * 3 * 4, 3 * 4 * 5, 4 * 5 * 6, 5 * 6 * 7));
      }

Output:
      lcm(2 * 3, 3 * 4, 4 * 5) = 60
      lcm(2 * 3 * 4, 3 * 4 * 5, 4 * 5 * 6) = 120
      lcm(2 * 3 * 4, 3 * 4 * 5, 4 * 5 * 6, 5 * 6 * 7) = 840

See also
	gcd	computes the greatest common divisor of two integers
	(C++17) (function template)

http://cppreference.com 	   2024.06.10			     std::lcm(3)
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