Question

3. Write a program to calculate factorials, n! Use a recursive function (i.e. a function that calls itself). If you use int's, what is the largest value of n that will give a correct value of n!? o If you use double's and use Stirling'se formula -for approximating factorials, what is the largest value of n that you can use in this case?

use c++ and type it out as how you would use put it in code

Answer 1

#include <iostream>
using namespace std;
int factorial(int n) {
   if ((n==0)||(n==1))
      return 1;
   else
      return n*factorial(n-1);
}
int main() {
   int n;
   cout<<"Enter value of n: ";
   cin>>n;
   cout<<"Factorial of "<<n<<" is "<<factorial(n);
   return 0;
}

Result compiled and executed in 6.024 sec(s) Enter value of n: 16 Factorial of 16 is 2004189184

If we use int then the maximum value of n which will give correct result is 16,if we give n as 17 we will not get correct response.

If we use double then the maximum value of n is 170 for which we will get correct response,if we give n as 171 then we will get result as infinite.