// This program demonstrates the use of recursion to create
// functions with the example of a fibonacci sequence
// Sasha Vassar Week09 Lecture 16

// Think of the example of fibonacci numbers, where each number
// is the sum of the previous two numbers. 
// So sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21....

// So what do we think would be the stopping case? == 0 return 0; 
// What about the recursive case?


#include <stdio.h>

int fibonacci(int number);

int main(void) {
    int number;
    printf("Enter fibonacci number: ");
    scanf("%d", &number);
    printf("fibonacci(%d) is %d\n", number, fibonacci(number));
    return 0;
}

//Let's write our function!

int fibonacci(int number) {
    //Stopping case
    if (number == 0) {
        return 0;
    } else if (number == 1) { 
        return 1;
    } else { // Recursive case
        return fibonacci(number-1) + fibonacci(number-2);
    }
}