Write a function that returns n!.
Solve this problem recursively.
Interface
C++ | int factorial(int n); |
C | int factorial(int n); |
Java | public static int factorial(int n); |
Python | factorial(n) # returns int |
factorial(n: int) -> int |
Precondition
Assume 0≤ n ≤ 12.
Observation You only need to submit the required procedure; your main program will be ignored.
Input/Output