Wrong output in recursive fibonacci number program - recursion

Question

I have written the program to print fibonacci numbers upto the limit as the user wants. I wrote that program in recursive fashion which should give the output as expected. It is giving the right output but with appended wrong values too. This happens if the user wants to print 4 or more than 4 fibonacci numbers. Also in the recursive function I have decreased the count value before passing it in the same function call. If i decrease the count value in the called function parameters then the while loop runs endlessly. When the loop finishes after some steps and the user limit input is 5 then the output is
Enter the limit number....
5
Fibonacci numbers are: 0 1 1 2 3 3 2 3 3
Finished.........
Can anyone tell me the fault in my program or the exact reason behind this output. Thanks in advance for it.
Program is as follows:
public class FibonacciNumbers
{
public static void main(String[] args)
{
int i=0, j=1;
Scanner sc = new Scanner(System.in);
System.out.println("Enter the limit number....");
int num = sc.nextInt();
System.out.print("Fibonacci numbers are: " + i + " " + j + " " );
fibonacci(num-2, i, j);
System.out.println("\nFinished.........");
}
public static void fibonacci(int count, int i, int j)
{
int sum = 0;
while(count > 0)
{
sum = i+j;
i=j;
j=sum;
System.out.print(sum + " ");
--count;
fibonacci(count, i, j);
}
}
}

Answer 1

You don't need both the while loop AND the recursive function calls. You have to choose between using a loop OR recursive calls.
The recursive solution:
public static void fibonacci(int count, int i, int j) {
if (count>0){
int sum = i+j;
i=j;
j=sum;
System.out.print(sum + " ");
--count;
fibonacci(count, i, j);
}
}
The solution involving a loop:
public static void fibonacci(int count, int i, int j) {
int sum = 0;
while(count > 0) {
sum = i+j;
i=j;
j=sum;
System.out.print(sum + " ");
--count;
}
}
The problem with your code
If you look closely at the following output of your code, you can see that in the beginning of the output there are the actual 7 first fibonacci numbers, and after that comes an unneeded series of the same fibonacci numbers. You printed two numbers from main, and then you expected 5 more numbers but got 31:
Enter the limit number.... 7
Fibonacci numbers are: 0 1 1 2 3 5 8 8 5 8 8 3 5 8 8 5 8 8 2 3 5 8 8 5
8 8 3 5 8 8 5 8 8
This happens because when you first call the fibonacci function with count=5, the while loop has 5 iterations, so it prints 5 fibonacci numbers and the fibonacci function is called 5 times from there with these count parameters: 4,3,2,1,0. When the fibonacci function is called with the parameter count=4, it prints 4 numbers and calls fibonacci 4 times with these parameters: 3,2,1,0 because the while loop then has 4 iterations. I drew an image of the recursive calls (I omitted the f(0) calls because they don't print anything):
If you add it all up, you can see that the program prints 31 fibonacci numbers altogether which is way too much because you wanted to print only 5! This trouble is caused by using while and recursive calls at the same time. You want the recursive behaviour to be like this instead, with no while loop:
OR you want one while loop and no recursion: