Count Repeated Numbers in a Range | Dataford Interview Questions

For an EPAM Systems QA validation utility, implement a function that counts how many times the digit 8 appears when writing every integer in an inclusive range from start to end. Count repeated occurrences within the same number separately. For example, 88 contributes two occurrences.

Your solution must avoid enumerating every number in the range. Use positional digit counting so that the algorithm remains efficient when the range contains very large values.

Formal Specification

Implement count_eights(start, end).

Input: Two non-negative integers, start and end, where start <= end.
Output: An integer representing the total number of digit 8 occurrences in all numbers from start through end, inclusive.
Leading zeros are not written and must not be counted.

Constraints

0 <= start <= end <= 10^18
The range may contain too many values for direct iteration
Only the digit 8 is counted
Numbers are written without leading zeros

Function Signature

def count_eights(start, end):

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