[modulo/devisor] sum up digit

문제 : Implement a function that returns the sum of the digits of an integer.

Examples:

1234 => 1 + 2 + 3 + 4 = 10

100001  => 1 + 1 = 2 

 

sol 1. iterative method

def sum_of_digits(number):
	
    sum = 0
	
    while number:
		sum += number % 10
		number //= 10
	
    return sum

sol2. recursive 

def sum_of_digits(number):
	if number == 0: return 0
	return (number % 10) + sum_of_digits(number//10)