Solved

Java long division in finite field 2

Posted on 2011-09-14
8
361 Views
Last Modified: 2012-05-12
How do I do a long division in galois field 2 in java?
0
Comment
Question by:humansg
  • 4
  • 2
8 Comments
 
LVL 59

Expert Comment

by:Kevin Cross
ID: 36539976
humansg, before we get started, is this for a homework assignment? If so, do you know how to work out the long division manually as I can help you translate that to Java, thus helping you "learn" versus just spitting out an answer...
0
 

Author Comment

by:humansg
ID: 36543181
yes, it is part of an assignment which I need to call for part of euclid algorithm..
yes i know how to do the long division manually.
0
 
LVL 59

Expert Comment

by:Kevin Cross
ID: 36543269
Okay. Great. Please post what you have for the calculation as you understand it in your attempt in Java. If you are getting any compilation or run-time errors, then you should post details on those. For run-time errors, posting the full stack trace in a code snippet is very useful. If the issue is logical, i.e., everything compiles and runs but you are not getting the expected results, then ensure to post what you expect alongside what you are getting currently.

From there, we can guide you through correcting the code.
0
Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

 

Accepted Solution

by:
humansg earned 0 total points
ID: 36556907
public static int gf2LongDivideQ(int dividend, int divisor) {

        int dividendLength = getLengthOf(dividend);
        int divisorLength = getLengthOf(divisor);

        if (divisorLength > dividendLength) {
            return -1;
        }

        int tempDividend = 0;

        int quotient = 0;

        for (int i = 1; i <= dividendLength; i++) {
            int bitAtPositionI = getBit(dividend, i);

            tempDividend = (tempDividend << 1) + bitAtPositionI;

            if (getLengthOf(tempDividend) < divisorLength) { // cannot divide
                // append '0' to end of quotient
                quotient = (quotient << 1);
            } else {
                // perform xor operation
                tempDividend = tempDividend ^ divisor;

                // append '1' to end of quotient
                quotient = (quotient << 1) + 1;
            }
        }

        return quotient;
    }

    public static int getLengthOf(int input) {
        int length = 0;
        while (input != 0) {
            input = input >> 1;
            length++;
        }
        return length;
    }

    public static int getBit(int input, int index) {
        input = input >> (getLengthOf(input) - index); // shift out bits to the right by (length - index)
        input = input & 0x1; // get right most bit
        return input;
    }

Open in new window

0
 

Author Closing Comment

by:humansg
ID: 36585517
Coded out myself. Should be able to work..
0
 

Author Comment

by:humansg
ID: 36556915
accepting own solution..
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Properties of numbers 14 57
servlet example 17 52
Java program running SQL query 5 37
running on tomcat not jboss eap 7.0 3 18
Article by: Nadia
Suppose you use Uber application as a rider and you request a ride to go from one place to another. Your driver just arrived at the parking lot of your place. The only thing you know about the ride is the license plate number. How do you find your U…
Article by: Nadia
Linear search (searching each index in an array one by one) works almost everywhere but it is not optimal in many cases. Let's assume, we have a book which has 42949672960 pages. We also have a table of contents. Now we want to read the content on p…
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

829 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question