【LeetCode】258. Add Digits 解题小结
题目:
Given a non-negative integer num
, repeatedly add all its digits until the result has only one digit.
For example:
Given num = 38
, the process is like: 3 + 8 = 11
, 1 + 1 = 2
. Since 2
has only one digit, return it.
参考这一篇wiki百科
https://en.wikipedia.org/wiki/Digital_root
class Solution { public: int addDigits(int num) { if (num >= 0 && num < 10) return num; return (num - 9 * ((num-1)/9)); } };