Comp Sci Java - calculate nth Fibonacci number

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To calculate the nth Fibonacci number in Java using a loop, the user should first prompt for input and store it in an integer variable. A "for" loop can be set up to iterate from 2 to n, where each Fibonacci number is computed by summing the two preceding numbers. It is recommended to store calculated Fibonacci numbers in an array to avoid redundant calculations and facilitate quick access. The first two Fibonacci numbers, F_0 and F_1, should be initialized in the array. This approach ensures an efficient calculation of the nth Fibonacci number.
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Homework Statement



Hello everyone, I am trying to write a java program that asks the user to input a number n, and the computer calculates the nth Fibonacci number. I am supposed to use a loop to calculate the problem.

My question is, how do I set up the loop to calculate the nth Fibonacci number? I know how to do all of the program except the loop.

Homework Equations



I want to use the "for" loop.

The Attempt at a Solution



import java.util.Scanner;

public class Assignment2 {
public static void main(String [] args) {
Scanner input = new Scanner(System.in);

System.out.print("Enter a number n in order to calculate the nth Fibonacci number: ");
int n = input.nextInt();

for(int i = 0; i;){}

System.out.println("The " + n + "th Fibonacci number is: ");

}
}
 
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Hercuflea said:

Homework Statement



Hello everyone, I am trying to write a java program that asks the user to input a number n, and the computer calculates the nth Fibonacci number. I am supposed to use a loop to calculate the problem.

My question is, how do I set up the loop to calculate the nth Fibonacci number? I know how to do all of the program except the loop.

Homework Equations



I want to use the "for" loop.

The Attempt at a Solution



import java.util.Scanner;

public class Assignment2 {
public static void main(String [] args) {
Scanner input = new Scanner(System.in);

System.out.print("Enter a number n in order to calculate the nth Fibonacci number: ");
int n = input.nextInt();

for(int i = 0; i;){}

System.out.println("The " + n + "th Fibonacci number is: ");

}
}

When you post code, put it inside [noparse]
Code:
[/noparse] tags. This makes your code easier to read, by preserving your indentation (if you used any).

You can't write a program to calculate Fibonacci numbers if you don't know how to calculate them yourself. What are the first few numbers in a Fibonacci sequence?
 
Mark44 said:
When you post code, put it inside [noparse]
Code:
[/noparse] tags. This makes your code easier to read, by preserving your indentation (if you used any).

You can't write a program to calculate Fibonacci numbers if you don't know how to calculate them yourself. What are the first few numbers in a Fibonacci sequence?

a1 = 0, a2 = 1, a3 = 1, a4 = 2, a5 = 3, a6 = 5, ...etc. adding the last two numbers to get the nth number.
 
Hercuflea said:
a1 = 0, a2 = 1, a3 = 1, a4 = 2, a5 = 3, a6 = 5, ...etc. adding the last two numbers to get the nth number.

Usually the indices start at zero, so that F_0=0, F_1=1, F_2=1, F_3=2,etc.

I would suggest that you store all calculated Fibonacci numbers in an array of Integers. To start with, you will need to initialize the array to include F_0 and F_1. Then, to calculate the nth number, you first look in the array to see if it has already been calculated; if yes then simply output that entry in the array, if no, then start with the last 2 entries in the array an calculate and store (in the array) all the remaining numbers up until the nth number.
 

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