@@ -0,0 +1,547 @@
+package Chapter01.Section01;%0A%0Apublic class Exercise20%0A%7B%0A    public static void main(String%5B%5D args)%0A    %7B%0A        if (args.length == 1)%0A        %7B%0A            long arg = Long.parseLong(args%5B0%5D);%0A            System.out.println(%0A                %22ln(%22 + arg + %22!) = %22%0A                + lnFactorial(arg));%0A        %7D%0A    %7D%0A%0A    public static double lnFactorial(long N)%0A    %7B%0A        return Math.log(factorial(N));%0A    %7D%0A%0A    public static long factorial(long N)%0A    %7B%0A        if (N %3C= 1)%0A            return 1;%0A%0A        return N * factorial(N-1);%0A    %7D%0A%7D%0A

Solved 1.1.20