Recursive multiplication and Karatsuba

[jsp01]

Hey everyone, I've got a question where I'm sort of stuck on writing a java code for a recursive "school method" multiplication where we have input 'n' and two n digit numbers 'a' and 'b' where the output is m=a.b. I also have to use an array representation for representing numbers. Could anyone please help me out? Thanks

The basic format is a=a1.B^(k) + a0 and b=b1.B^(k) + b0 where a.b=a1.b1.B^(2k)+(a1.b0+a0.b1).B^(k)+a0.b0 and k=floor(n/2)

Also then how would you use this and implement a Karatsuba multiplication if say n>3.

[Darryl.Burke]

Cross posted all over
http://www.java-forums.org/new-java/40500-recursive-multiplication-karatsuba.html
http://javaprogrammingforums.com/algorithms-recursion/7920-recursive-multiplication-karatsuba.html
http://www.programmersheaven.com/mb/java/422411/422411/recursive-multiplication-and-karatsuba/
http://www.coderanch.com/t/530565/java/java/Recursive-multiplication-Karatsuba

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