Question

This java code won't run and I can't figure out the problem with it. Please help

import java.io.*;
import java.util.*;
import java.math.*;
import java.util.Scanner;

public class Fibonacci
{
   // Returns n-th Fibonacci number
   static BigInteger fib(int n)
   {
       BigInteger[] Fibo = new BigInteger[n+2];
Fibo[0] = BigInteger.ZERO;
Fibo[1] = BigInteger.ONE;
  
       for (int j=2 ; j<=n ; j++)
       {
           Fibo[j] = Fibo[j-1].add(Fibo[j-2]);
       }
  
return (Fibo[n]);
}

   public static void main(String[] args)
   {
       Scanner sc= new Scanner(System.in);
       int n = sc.nextInt();
       long start = System.currentTimeMillis();
       System.out.println("Fibonacci of " + n +
           "th term" + " " +"is" +" " + fib(n));
       long end = System.currentTimeMillis();
System.out.println("Time taken for computation is " +
(end - start) + "ms");
   }
}

Answer 1

import java.math.BigInteger;
import java.util.Scanner;

public class Fibonacci {
    // Returns n-th Fibonacci number
    static BigInteger fib(int n) {
        BigInteger[] Fibo = new BigInteger[n + 2];
        Fibo[0] = BigInteger.ZERO;
        Fibo[1] = BigInteger.ONE;
        for (int j = 2; j <= n; j++) {
            Fibo[j] = Fibo[j - 1].add(Fibo[j - 2]);
        }
        return (Fibo[n]);
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a value for n: ");
        int n = sc.nextInt();
        long start = System.currentTimeMillis();
        System.out.println("Fibonacci of " + n + "th term" + " " + "is" + " " + fib(n));
        long end = System.currentTimeMillis();
        System.out.println("Time taken for computation is " + (end - start) + "ms");
    }
}

// This works correctly.

// But there was no input prompt.

// I've added an input prompt to make it easier to input a number. I've provided output screenshot as well.