C Program - Write a recursive function to calculate the nth Fibonacci number. Use this function in main to display the first n Fibonacci numbers. The recursive definition of nth Fibonacci number is as follows

 fib(n) = 1                                  if n = 1 or 2
           = fib(n-2) + fib(n-1)       if n>2  

Program

#include <stdio.h>
int fibo(int);
int main()
{
    int num;
    int result;

    printf("Enter the nth number in fibonacci series: ");
    scanf("%d", &num);
    if (num < 0)
    {
        printf("Fibonacci of negative number is not possible.\n");
    }
    else
    {
        result = fibo(num);
        printf("The %d number in fibonacci series is %d\n", num, result);
    }
    return 0;
}
int fibo(int num)
{
    if (num == 0)
    {
        return 0;
    }
    else if (num == 1)
    {
        return 1;
    }
    else
    {
        return(fibo(num - 1) + fibo(num - 2));
    }
}

Output:

Enter the nth number in fibonacci series: 10
The 10 number in fibonacci series is 55