Binary Searches in an array (sorted already)

Last one, I promise....

I have to do a lab for school.  I need help with making a binary search in a one-dimensional array that has been sorted using the bubble method.  i know about the first and last then average, etc., but i have no idea actually how to code that. and everthing....please help
weinrjAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

kellyjjCommented:
when you say binary sort, are you talking about comparing the byte value of each element of the array?
0
weinrjAuthor Commented:
I meant a binary search.  My teach. calls it that because it
cuts it half in time with sequentional search.  I believe it
takes top and last number, averages, etc. until it found it.
0
NexialCommented:
From D. Knuth "The Art of Computer Programming", Volume 3 (first edition): P. 407


"Algorithm B (Binary Search).   Given a table of records R1, R2,...,Rn whose keys are in increasing order K1 < K2 < ... < Kn then this algorithm searches for a given argument K.

B1. [Initialize.] Set l <- 1, u <- N

B2. [Get midpoint.] (At this point we know that if K is in the table, it satisfies Kl <= K <= Ku.  A more precise statement of the situation appears in exercise 1 below.)  If u < l, the algorithm terminates unseuccessfully.   Otherwise set i <- floor((l+u/2)), the approximate midpoint of the relevant table area.

B3. [Compare.] If K < Ki goto B4;  if K > Ki, goto B5; and if K=Ki the algorithm terminates successfully.

B4. [Adjust u.] Set u <- i -1 and return to B2.

B5. [adjust l.] Set l M- i + 1 and return to B2."
======================================================
u = upper bound,
l = lower bound
The floor function produces the greatest integer <= its argument.

The materials in exercise 1 are not needed, as they deal with the tightness of the bounding conditions, and are irrelevant to the code.

"Although the basic idea of binary search is comparatively straightforward, the details can be somewhat tricky, and many good programmers have doe it wrong the first few times they tried.   One of the most popular correct forms of the algorithm makes use of two pointers, l and u, which indicate the current lower and upper limits for the search"

BE ESPECIALLY CAREFUL OF THE +/- 1 being added to the pointers in B4 and B5.

0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
weinrjAuthor Commented:
thanks....it was a tad too confusing, i am in computer science
I in H.S.  I will experiment what you want me to do.  
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Pascal

From novice to tech pro — start learning today.