/* Write and test a method mult with the following specification without using the multiplication operator. Write a recursive method that performs the multiplication by repeated addition. Make your method work for both positive and negative integers, as well as zero. Start by calling a separate helper method that assumes both parameters are nonnegative. Then, in the calling method, make an adjustment afterwards for the case when the signs of the two original numbers were different. PARAMETERS: integers j and k RETURN VALUE: the product j*k */ long mult(long j, long k);