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$ curl repovive.com/roadmaps/math-fundamentals/arithmetic-modulo/add-digits-implementation

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$ curl repovive.com/roadmaps/math-fundamentals/arithmetic-modulo/add-digits-implementation

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Add Digits - Implementation - Arithmetic & Modulo | Math Fundamentals | Repovive

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Math Fundamentals18 sections · 842 units13h total

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Add Digits - Implementation

In pseudocode

Here's the mathematical solution:


function addDigits(n)
    if n = 0 then
        return 0
    return 1 + ((n - 1) mod 9)

For $n = 38$ : $(38 - 1) \bmod 9 = 37 \bmod 9 = 1$ , so the answer is $1 + 1 = 2$ . This matches the loop result but finishes in constant time.