Operations on very large binary numbers

Question

Hi guys,
I'm trying to write a java class for manipulations of very large binary numbers.
I'm representing the BN internally as boolean[] (array of booleans false for 0 & true for 1).
I want to write an algorithm for the following operations :
shifLeft (boolean[] b,int n) : shifting binary number to left by n positions.preferably a circular shift .
and also the corresponding shiftRight() method.
can some one guide me on how to implement this ?
thanks.

Answer 1

Consider an array of ascii chars....
array =>   | |a|b|c|d|
offset = 1
len = 4In the above there are actually five spots in the
array but the offset points to the second position in
the array and the length is 4.
If I was to extract the value it would be "abcd"
because of the offset and the length.
Now a 'shift right' means that if it is "abcd" then
it should now be "abc" (because the d fell off the
end.)
I can do that like this.
array =>   | |a|b|c|d|
offset = 1
len = 3Notice in the above that nothing changed except the
length. But because the length changed if I
extracted the value I would get "abc" because the
offset is 1 and the length is three.
Notice also that there was no array copying.Are you sure shifting works like that ?
what I know about left shifting is that the 'd' should be moved left -toghether with a, b, c- and we append a 0 in place of 'd' .
from what you said the 'd' would be gone , or am I again wrong ?
it seems i still didn't get any satisfactory answer to this problem...