tut_18.cpp

#include<iostream>
using namespace std;

// /********Recursions & Recursive Functions in C++ **********/

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

// step by step calculation of factorial(4)
    // 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 fib(int n){
    if(n<2){
        return 1;
    }
    return fib(n-2) + fib(n-1);
}

int main(){
    int a;
    cout<<"Enter a number: "<<endl;
    cin>>a;
    //cout<<"The factorial of "<<a<<" is "<<factorial(a)<<endl;
    cout<<"The term in fibonacci sequence at position "<<a<<" is "<<fib(a)<<endl;
    return 0;
}