Add Digits, is a LeetCode problem. In this post we will see how we can solve this challenge in C++

Problem Description

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.

Follow up: Could you do it without any loop/recursion in O(1) runtime?

Credits:Special thanks to for adding this problem and creating all test cases. ....

You can find the full details of the problem Add Digits at LeetCode

Solution: Please check the main.cpp snippet for the solution.

This solution originally posted at: Github by @kamyu104