First clarify the problem: extract all odd digits from the integer, sort them in ascending order, and concatenate to form the smallest possible integer. Then discuss edge cases such as no odd digits, leading zeros, and negative numbers, and analyze time and space complexity.
Pro tip: Mention that leading zeros are naturally avoided because sorting odd digits ascending places the smallest non-zero digit first, but if all odd digits are zero, the result is 0. Also, consider negative numbers: the smallest integer from odd digits of a negative number should be the negative of the largest possible integer formed by those digits (i.e., sort descending and negate).
Confirm that only odd digits are considered, even digits are ignored, and the goal is to form the smallest possible integer. Ask about negative numbers, leading zeros, and whether the input is a string or integer.
Iterate through the digits of the integer (or its string representation) and collect all odd digits into a list.
Sort the list of odd digits in ascending order. If the number is negative, sort in descending order to get the smallest (most negative) integer. Concatenate the sorted digits to form the result.
If no odd digits exist, return 0 or indicate no valid integer. If the result has leading zeros (e.g., all odd digits are zero), the integer is 0. For negative numbers, apply the sign after sorting.
State that time complexity is O(d log d) where d is the number of odd digits (due to sorting), and space complexity is O(d) for storing the digits.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
The dedup-per-store part is what makes this non-trivial.
Clarify that the goal is to find comments with the highest global frequency, where each store contributes at most one count per comment. Use a two-level aggregation: first deduplicate comments within each store, then count global occurrences across stores. Finally, identify the comment(s) with the maximum count, handling ties appropriately.
Pro tip: Mention that you would validate the input for edge cases like empty stores or empty comment lists, and discuss how to handle ties (e.g., return all tied comments). This shows attention to detail and production readiness.
Confirm that duplicates within a store count once, and that we need the most frequent comment(s) globally. Ask about tie-breaking and empty inputs.
For each store, convert its list of comments to a set to remove duplicates, ensuring each comment is counted at most once per store.
Iterate over each store's unique comments and increment a global frequency dictionary for each comment.
Determine the highest count from the global frequency dictionary.
Collect all comments whose global count equals the maximum and return them as the result.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
Clarify how sessions are distributed across years (e.g., evenly or all in one year) and whether overlapping years count multiple times. Then, for each possible pair of consecutive years, compute the total sessions from all classes that overlap those years, and return the maximum. Use a sweep-line or interval-based approach to efficiently compute the sums.
Pro tip: Discuss the ambiguity of session distribution and propose a reasonable assumption (e.g., sessions are evenly distributed across the class's active years) to show you think about data realism. Also, mention that if sessions are concentrated in specific years, you'd need more granular data.
Ask how sessions are distributed across years (evenly, all in start year, etc.) and whether a class active in both years counts its sessions once or twice. Confirm the definition of 'combined number of sessions'.
For a given pair of consecutive years (y, y+1), sum the sessions of all classes whose active period overlaps with either year. If sessions are evenly distributed, compute the fraction of the class's total sessions that fall in those years.
Use a sweep-line over years or precompute prefix sums of sessions per year to evaluate all consecutive year pairs in O(n log n) or O(n + Y) time, where Y is the range of years.
Consider classes with start year > end year (invalid), classes spanning only one year, and years with no classes. Test with small examples to ensure correctness.
State the time and space complexity of your solution and discuss potential optimizations or alternative approaches (e.g., if sessions are not evenly distributed).
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.