closeHello! Click here if you would like to know what Factolex is about.

Addition-subtraction chain

Start collecting facts
These are the best facts for Addition-subtraction chain, collected by our users from the web:
(You can find the source through the icon at the end of each fact)
  1. a generalization of addition chains to include subtraction, is a sequence a0, a1, a2, a3, ... that satisfies An addition-subtraction chain for n, of length L, is an addition-subtraction chain such that aL = n

    Source: Wikipedia Unhappy with this fact? more info
    created by user picturefactobot on February 11, 2009
  2. That is, one can thereby compute n by L additions and/or subtractions. (Note that n need not be positive. In this case, one may also include a-1=0 in the sequence, so that n=-1 can be obtained by a chain of length 1.) By definition, every addition ch

    Source: Wikipedia Unhappy with this fact? more info
    created by user picturefactobot on February 11, 2009
  3. Therefore, the length of the shortest addition-subtraction chain for n is bounded above by the length of the shortest addition chain for n

    Source: Wikipedia Unhappy with this fact? more info
    created by user picturefactobot on February 11, 2009
  4. In general, however, the determination of a minimal addition-subtraction chain (like the problem of determining a minimum addition chain) is a difficult problem for which no efficient algorithms are currently known

    Source: Wikipedia Unhappy with this fact? more info
    created by user picturefactobot on February 11, 2009
  5. The related problem of finding an optimal addition sequence is NP-complete (Downey et al., 1981), but it is not known for certain whether finding optimal addition or addition-subtraction chains is NP-hard

    Source: Wikipedia Unhappy with this fact? more info
    created by user picturefactobot on February 11, 2009
Do you know more? Submit a new fact

Add a new fact

A fact should only contain one sentence, describing an aspect of the term.

Fact
Example: located on the west coast of the U.S
Source
Tags
optional

Example: geography location -- separate tags with spaces

Add one more fact or give me some inspiration from:

More lexica »Featured Lexica

Look at what our users have created already.

Feedback

Please tell us what you think about our project

Contribute

On Factolex you can add facts and terms that you believe are missing.

To be sure that the term hasn't already been entered, please use the search function before doing so.

Home  |  About  |  FAQ  |  Feedback  |  Tools  |  Stats  |  Contact Us  |  API  |  Blog
Change language to: