JavaScript: Greatest Common Divisor (최대 공약수), Least Common Multiple (최소 공배수)

정수론 (1) - 최대공약수, 최소공배수, 유클리드 호제법

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Greatest Common Divisor (최대 공약수)
:the greatest common divisor of two or more integers is the largest positive integer that divides each of the given integers without leaving a remainder.

function GCD(x, y) {
  return !x ? y : GCD(y, x % y);
}

!b: to check if the value of b is equal to 0. (! = (logical NOT))
If it is, the function returns a as the greatest common divisor.

If b is not equal to 0, the function calls itself recursively, passing b as the new value of a and the remainder of a divided by b (a % b) as the new value of b. 
This process continues until b becomes 0, at which point the function returns a as the greatest common divisor.

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Least Common Multiple (최소 공배수)
The GCD represents the largest positive integer that divides both x and y without leaving a remainder. 

  function LCM(x, y) {
    return (x * y) / GCD(x, y);
  }

1. The GCD(x, y) function is called to calculate the GCD of x and y. 
2. The product of x and y is divided by the GCD using the division operator /.
3. The result is the LCM of x and y.

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