@@ -0,0 +1,251 @@
+// http://codingbat.com/prob/p116624%0A%0Apublic int diff21(int n) %7B%0A  int difference = n - 21;%0A  if (n %3C= 21) %7B%0A    return (difference %3E 0) ? difference : -difference;%0A  %7D%0A  else %7B%0A    return (difference %3E 0) ? 2 * difference : 2  * (-difference);%0A  %7D%0A%7D%0A

Create diff21.java