Greatest common divisor

The greatest common divisor of two integers is the largest integer that divides them both. If numbers are 121 and 143 then greatest common divisor is 11.

There are many methods to calculate this. For example, the division-based Euclidean algorithm version may be programmed

Function GreatestCommonDivisor

function GreatestCommonDivisor(a, b: Int64): Int64;
var
  temp: Int64;
begin
  while b <> 0 do
  begin
    temp := b;
    b := a mod b;
    a := temp
  end;
  result := a
end;

See also

• Pascal - Basic Maths 3 - Greatest Common Divisor (gcd) using Euclid's Algorithm
• Least common multiple
• Mod