Sum of Digits — Solution & Editorial
Repeatedly take N mod 10 and divide by 10, or process the number as a string.
Complexity: O(number of digits)
Watch out: N does not fit in 32 bits — read it as a 64-bit integer or a string.
Repeatedly take N mod 10 and divide by 10, or process the number as a string.
Complexity: O(number of digits)
Watch out: N does not fit in 32 bits — read it as a 64-bit integer or a string.