What is GCD?
The greatest common divisor (gcd) of two or more integers is the largest positive integer that divides each of the integers. For example, the gcd of 8 and 12 is 4. It is also known as the greatest common factor (gcf), highest common factor (hcf), greatest common measure (gcm), or highest common divisor.
What is LCM?
The least common multiple, lowest common multiple, or smallest common multiple of two integers a and b, usually denoted by LCM(a, b), is the smallest positive integer that is divisible by both a and b.
What is LCD?
The lowest common denominator or least common denominator (abbreviated LCD) is the lowest common multiple of the denominators of a set of fractions.
Regarding our problem, we can make functions to calculate GCD and LCM.
func gcd(numerator: Int, denominator: Int) -> Int
{
if (numerator == 0) {
return denominator;
} else {
return gcd(numerator: denominator % numerator, denominator:numerator);
}
}
func lcm(numerator: Int, denominator: Int) -> Int {
return (numerator * denominator) / gcd(numerator: numerator, denominator: denominator);
}
let lcd = lcm(numerator: f1.denominator, denominator: f2.denominator)
//use it in further calculation
Now to add, multiply, divide or subtract, all we need to do is to pass the numerator and denominator.
GCD HCF LCM