sona11

sona11

Fibonacci series using java

I wrote this code to calculate Fibonacci numbers by specifying the size. The results are correct, however the one thing that concerns me is the negative sign for some numbers in the larger range of size input.
here is the code

import java.util.Scanner;

public class FibonacciSeries {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int a, c = 0;
        int result = 0;
        int b = 1;

        Scanner scan = new Scanner(System.in);
        System.out.println("Enter the Number to display Fibonacci Series");
        a = scan.nextInt();

        System.out.println("Fibonacci Seriers is as follows");


        for (int i = 1; i <= a; i++) {
            System.out.print(" "+result+" ");
            result = c + b;
            b = c;
            c = result;

        }

    }

}

As previously said, this function calculates fibonacci numbers by selecting the size. I read the article about it here according to that findings are right however the one thing that bothers me is the negative sign for some values in the greater range of size input.

1- I couldn’t identify a mistake in the code; how can I remove the negative values from the output?
2- Why are there positive values following certain negative values? 3- The first negative value is -1323752223, followed by a positive number.

Thank you very much.

Most Liked

mindriot

mindriot

The problem you are having is integer overflow. The int allocates enough memory to hold a number within a range (specifically 32 bits giving a range of 2^-31 through 2^31 which is -2147483648 to 2147483647), when you add two numbers together and the result is larger then this than it overflows the memory available. Due to the way in which numbers are represented and added in binary, the effect it has is that it wraps around so 2147483647 + 1 = -2147483648.

You can look into integer overflows, to fully understand what is happening it is best to look at how numbers are represented in binary, twos complement, and how to do addition/subtraction. However for the problem at hand you have two options.

First you can use a long which allocates twice as much memory for the numbers and will give you a much larger range before you run into the same problem, but you will run into the same problem with big enough numbers. This is the easiest option, you should be able to just change “int” to “long” when declaring the variables and you will be good.

Alternatively you can look at something like the BigInteger class which will be able to allocate the right amount of memory to hold larger numbers as required, with some small costs in performance and being more awkward to use in some situations.

Where Next?

Popular Backend topics Top

wolf4earth
At work we plan to replace a totally overkill Kafka instance with a combination of SNS and SQS. I don’t want to get into a discussion on ...
New
TwistingTwists
Hello Folks, I am a novice developer from India. Intending to learn Elixir and web apps (phoenix framework). What are things that I MUS...
New
bsek43
Hello everyone, I’ve started learning Elixir and Phoenix few months ago and while I mostly grasped Elixir’s functional concepts and Phoe...
New
sampu
I have a use case where a client is invoking a Rest endpoint via a load balancer, which in turn invokes a third party endpoint which is r...
New
Fl4m3Ph03n1x
Background So, I am playing around with a concept named “NewType” and I am taking inspiration from languages like F# and Scala. My objec...
New
harwind
I received this error for a binary search programme in C, despite the fact that it requested for inputs and produced the right output. Th...
/c
New
Fl4m3Ph03n1x
Background I have a phoenix application in Windows 11. Unfortunately for me, I cannot compile the application because of a dependency err...
New
jaeyson
Hi! I have clarifications (please correct me, as I mostly mix/confuse this details) with the following: The term RAG here where it read...
New
apoorv-2204
Anyone know how to get in golang? I am from elixir background?.
New
theodor
I have this app where there are a bunch of users that cannot access their account anymore after they updated their Android device to Andr...
New

Other popular topics Top

dimitarvp
Small essay with thoughts on macOS vs. Linux: I know @Exadra37 is just waiting around the corner to scream at me “I TOLD YOU SO!!!” but I...
New
AstonJ
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
PragmaticBookshelf
Rails 7 completely redefines what it means to produce fantastic user experiences and provides a way to achieve all the benefits of single...
New
PragmaticBookshelf
Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
PragmaticBookshelf
Author Spotlight Rebecca Skinner @RebeccaSkinner Welcome to our latest author spotlight, where we sit down with Rebecca Skinner, auth...
New
New
PragmaticBookshelf
Author Spotlight: VM Brasseur @vmbrasseur We have a treat for you today! We turn the spotlight onto Open Source as we sit down with V...
New
Fl4m3Ph03n1x
Background Lately I am in a quest to find a good quality TTS ai generation tool to run locally in order to create audio for some videos I...
New
mindriot
Ok, well here are some thoughts and opinions on some of the ergonomic keyboards I have, I guess like mini review of each that I use enoug...
New
PragmaticBookshelf
Use advanced functional programming principles, practical Domain-Driven Design techniques, and production-ready Elixir code to build scal...
New