tut18.cpp

#include<iostream>
using namespace std;


int fib(int n){
    if(n <= 1){
        return 1;
    }
    return fib(n-2) + fib(n-1);
}
int factorial(int n){
    if (n <= 1){
        return 1;
    }
    return n * factorial(n-1);
}

// Step by step calcualtion of factorial

// factorial(4) = 4 * factorial(3)
// factorial(4) = 4 * 3 * factorial(2)
// factorial(4) = 4 * 3 * 2 * factorial(1)
// factorial(4) = 4 * 3 * 2 * 1
// factorial(4) = 24


int main(){
    // Factorial of a number:
    // n! = n * (n-1)!
    int a;
    cout<<"Enter a number: "<<endl;
    cin>>a;
    cout<<"The factorial of "<<a<<" is "<<factorial(a)<<endl;
    cout<<"The "<<a<<"th term in Fibonacci sequence is "<<fib(a)<<endl;
    return 0;
}