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Leetcode
Easy
Math
Number Theory
Add Digits
Repeatedly add the digits of a non-negative integer until a single digit remains.
Acceptance 0%
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Problem Statement
Given a non-negative integer, repeatedly replace the number with the sum of its digits until the result has only one digit. Return that final single-digit value.
For example, if the number is 38, then 3 + 8 = 11, and 1 + 1 = 2, so the answer is 2.
Input Format
- One non-negative integer
num. - The value may be provided as an integer.
Output Format
- Return the single digit obtained after repeatedly summing the digits of
num.
Constraints
0 <= num- The final answer is always a single digit from
0to9.
Examples
Sample cases returned by the problem API.
Example 1
Input
num = 38
Output
2
Explanation
3 + 8 = 11, and 1 + 1 = 2.
Example 2
Input
num = 0
Output
0
Explanation
The number is already a single digit.
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