Dsa
Math
Medium
Digital Root
Calculate the digital root of a non-negative integer n. The digital root is the iterative process of summing the digits of the number until a single digit is obtained. For example, the digital root of 493193 is 4 (4 + 9 + 3 + 1 + 9 + 3 = 29; 2 + 9 = 11; 1 + 1 = 2). Use the digital root formula: dr(n) = 1 + (n - 1) % 9 if n > 0 and dr(0) = 0.
Input:
A non-negative integer n.
Output:
The digital root of n.
Example:
Input:
493193
Output:
4
Key concepts
digitsrootmath
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