Fibonacci sequence
From CompSciWiki
Back to the Program-A-Day homepage
ProblemWrite a complete Java program Fibonacci that:
|
...by students
An image or By Students section | |
---|---|---|
SolutionIn order to get the user input by JOptionPane, you will first have to import the swing package. You can import swing package by import javax.swing.*; or import javax.swing.JOptionPane; Then, the next step is declaring variables; in this program we will need three int variables. One variable will be used as F(n) and another variable will be used as F(n-1). Our initial value for F(n) will be 1 and F(n-1) will be 0, referring to the fibonacci formula. (F(0) = 1, F(1) = 1) Once you declare the necessary variables, the last variable will be the casted integer from the user input. int n = 1 int n-1 = 0 String str = get the user input using JOptionPane int input = cast str to integer Once you have all the variables ready, make a for loop that starts from 0 and ends when the counter is less than n (user input). In this for loop, the increment will be by 1. for(count = 0; count < user input; count increment by 1) { } We will need another variable to keep track of F(n-2). You simply set it F(n-2) = F(n-1) as it starts a new iteration, and set F(n-1) = F(n). Then sum up the F(n-2) + F(n-1) which will now be F(n). (n-2) = (n-1) (n-1) = n n = (n-2) + (n-1) When the for loop ends, you will have exactly nth fibonacci number you wanted. At last, print it out using JOptionPane. See below for the code. | ||
Code |