Use the formulas s1 1 and sn sn1 n for n 2 to write a rec

Use the formulas s₁ = 1 and s_n = s_n1 · n for n 2 to write a recursive algorithm that computes s_n = n! You may use any style of pseudo-code to write your algorithm, but make sure that the steps of your algorithm are clear

Solution

PSEUDO-CODE

1. Factorial(parameter : n)
2.    if n equal to 1 then
3.       Return (1)
4.   else
5.       Return ((Call Factorial(argument: n-1))*n)
6. Call Factorial(argument: n)

ALGORITHM: Factorial(positive integer n)

Input: n positive integer
Output: factorial of n

Sample Run

Factorial(parameter : 4)
Factorial(parameter : 3) * 4
Factorial(parameter : 2) * 3 * 4
Factorial(parameter : 1) * 2 * 3 * 4
1 * 2 * 3 * 4

returns 24