recursion implementation in c++

#include <iostream>
using namespace std;

/*
POWER

int power( int n , int p){

if( p==0)
return 1;

return n * power(n , p-1) ;
}

*/

/*
FACTORIAL

int fact(int n){

if(n==0)
return 1;

return n * fact(n-1);
}

*/

/*
FABONACCI SERIES

int fabonacci ( int n){

if(n==1 || n==0)
return n;

return ( fabonacci(n-1) + fabonacci(n-2) );
}

*/

/*
SUM OF N NATURAL NUMBER

int sum( int n){

if(n==1)
return 1;

return ( n + sum(n-1) );
}

*/

int main()
{
/*

        finding the power of any number

cout << power(4,3);

*/

/*

        finding the factorial of any number

cout << fact(4);

*/

/*

        finding fabonacci of nth term

cout << fabonacci(5) ;

/*

/*
finding sum of n natural numbers

cout << sum(5);
return 0;

*/

}