NthFibbonacciNumber.java

// Nth Fibonacci Number
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// The n-th term of Fibonacci series F(n), where F(n) is a function, is calculated using the following formula -
//     F(n) = F(n - 1) + F(n - 2), 
//     Where, F(1) = 1, F(2) = 1

// Provided 'n' you have to find out the n-th Fibonacci Number. Handle edges cases like when 'n' = 1 or 'n' = 2 by using conditionals like if else and return what's expected.

// Example :
// Input: 6

// Output: 8

// Explanation: The number is ‘6’ so we have to find the “6th” Fibonacci number.
// So by using the given formula of the Fibonacci series, we get the series:    
// [ 1, 1, 2, 3, 5, 8, 13, 21]
// So the “6th” element is “8” hence we get the output.

import java.util.Scanner;

public class NthFibbonacciNumber {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        int n = s.nextInt();
        int f1 = 1, f2 = 1, fn = 0;
        if (n == 1 || n == 2) {
            fn = 1;
        } else {
            for (int i = 3; i <= n; i++) {
                fn = f1 + f2;
                f1 = f2;
                f2 = fn;
            }
        }
        System.out.println(fn);
        s.close();
    }
}