c#最小公倍数を求める

 1 class Program

 2     {

 3         static void Main(string[] args)

 4         {

 5             int n = m(20, 15);

 6             System.Console.WriteLine(" :" + n.ToString());

 7             System.Console.Read();

 8         }

 9 

10         static int f(int a, int b)//  

11         {

12             if (a < b) { a = a + b; b = a - b; a = a - b; }

13             return (a % b == 0) ? b : f(a % b, b);

14         }

15 

16         static int m(int a, int b)//  

17         {

18             return a * b / f(a, b);

19         }

20     }