factorial.py

classFactorial:
@staticmethod
deffactorial_iteration(number: int, use_while: bool=False) ->int:
factorial: int=1
ifnumber<0:
raiseArithmeticError("Factorial of a negative number doesn't exist.")
elifnotisinstance(number, int):
raiseArithmeticError("Factorial of non-integers is not supported.")
elifnumber==0ornumber==1:
returnfactorial
else:
ifuse_while:
i: int=1
whilei<number+1:
factorial*=i
i+=1
else:
foriinrange(1, number+1):
factorial*=i
returnfactorial

@staticmethod
deffactorial_recursion(number: int) ->int:
ifnumber<0:
raiseArithmeticError("Factorial of a negative number doesn't exist.")
elifnotisinstance(number, int):
raiseArithmeticError("Factorial of non-integers is not supported.")
elifnumber==0ornumber==1:
return1
else:
returnnumber*Factorial.factorial_recursion(number-1)


if__name__=='__main__':
input_number=int(input("Enter a positive integer: "))
print("Using iteration (for):", Factorial.factorial_iteration(input_number))
print("Using iteration (while):", Factorial.factorial_iteration(input_number, use_while=True))
print("Using recursion:", Factorial.factorial_recursion(input_number))