Number With Exclamation
This function should take a non-negative integer as an input and return the factorial of that number. The factorial of a non-negative integer n is the product of all positive integers less than or equal to n .
Input: Integer (int).
Output: Integer (int).
Examples:
assert factorial(0) == 1 assert factorial(1) == 1 assert factorial(5) == 120 assert factorial(10) == 3628800
How it’s used:
- in mathematical applications to calculate permutations and combinations;
- in algorithms to solve problems related to counting arrangements.
Precondition:
- n ∈ N₀
