Bloomberg·Software Engineer·Technical Phone Screen·Intermediate

Intermediate

Jun 2026

Summary

Bloomberg coding round, one question the whole time. The problem looked like a fun little string thing until the duplicate letter handling showed up and made me rethink everything I'd written.

Questions Asked (1)

Implement the feedback logic from a Wordle-style game: given a guess and a target of equal length, return per-character results indicating exact match, present but wrong position, or not present. Duplicate letters must be handled correctly so a letter isn't marked 'present' more times than it actually appears in the target once exact matches are removed.

Algorithms & Data Structures

Author's notes

I got the basic cases pretty fast, exact match is trivial, absent letters are trivial.

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AI HintsAI Generated

Suggested Approach

Use a two-pass approach: first mark exact matches and count remaining letters in the target, then for non-exact positions, mark 'present' if the letter still has remaining count, otherwise 'absent'. This ensures duplicates are handled correctly by decrementing counts only when a letter is consumed.

Pro tip: Clarify the output format upfront (e.g., array of enums or strings) and discuss edge cases like empty strings or different lengths, showing attention to detail and robustness.

1. Clarify requirements and edge cases

Confirm input/output format, character set, and handling of different lengths or empty strings. Discuss whether the function should be case-sensitive.

2. First pass: mark exact matches

Iterate through both strings simultaneously, marking positions where characters match exactly. Build a frequency count of the remaining characters in the target.

3. Second pass: mark present or absent

For non-exact positions, check if the guess character exists in the remaining target counts. If yes, mark as present and decrement the count; otherwise mark as absent.

4. Return results and discuss complexity

Return the array of results. Explain that the algorithm runs in O(n) time and O(1) extra space (since alphabet size is constant).

Key Points to Mention

Two-pass approach to avoid false positives with duplicate letters
Using a frequency map (or array) to track remaining letters after exact matches
Time complexity O(n) and space complexity O(1) for fixed alphabet
Edge cases: empty strings, different lengths, case sensitivity
Output format: array of enums or strings (e.g., 'correct', 'present', 'absent')
Importance of decrementing counts only when a letter is marked present

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.