How should I practice Count Digits 0, 2, and 4?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Capital One online assessment problems in FastPrep.

Is Count Digits 0, 2, and 4 associated with Capital One?

FastPrep tags this as a Capital One online assessment coding practice problem when the problem catalog has that company and stage context.

Problem · String

Count Digits 0, 2, and 4

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● Easy

Capital OneNEW GRADINTERNOA

Problem statement

Given a non-negative integer n, count how many times the decimal digits 0, 2, and 4 appear across all integers from 0 through n, inclusive.

Count every occurrence. For example, the number 22 contributes two occurrences of the digit 2.

A solution with time complexity no worse than O(n^2) fits within the execution limit.

Function

solution(n: int) → int

Examples

Example 1

n = 10return = 4

The digit 0 appears in 0 and 10, while 2 and 4 each appear once. The total is 2 + 1 + 1 = 4.

Example 2

n = 22return = 11

The digit 0 appears 3 times, the digit 2 appears 6 times, and the digit 4 appears 2 times. The total is 3 + 6 + 2 = 11.

Constraints

n is a non-negative integer.
The answer fits in a signed 32-bit integer.

Source note: Additional source evidence from September 4 and 5, 2026 Capital One CodeSignal online assessment reports.