Amazon interview notes, page 106 of 159

“Two passes: first to build a frequency count, second to scan for the first count-of-one.” The rest of the author's notes on Software Engineer interview at Amazon, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“My first instinct was to just group by userId upfront and then do a two-pointer sweep per user, which is basically O(n log n) for the grouping plus O(k) per user for the merge.” The rest of the author's notes on Software Engineer interview at Amazon, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“Classic sliding window problem once you see it, but I spent way too long overthinking the data structure for tracking counts.” The rest of the author's notes on Software Engineer interview at Amazon, Online Assessment (OA) round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“I almost sorted on (freq, -value) out of muscle memory because I'd practiced a version where ties break by descending value.” The rest of the author's notes on Software Engineer interview at Amazon, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“Got the two-heap setup pretty quickly, max-heap for the top, min-heap for the bottom, pop and push each round.” The rest of the author's notes on Software Engineer interview at Amazon, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“Took me a minute to realize this is just iterating over how many 4-wheelers you can fit and checking if the remainder is divisible by 2, which it always is as long as it's non-negative.” The rest of the author's notes on Software Engineer interview at Amazon, Online Assessment (OA) round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“The format is basically: here's a messy situation in your inbox, now reply like a professional.” The rest of the author's notes on Software Engineer interview at Amazon, Online Assessment (OA) round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“Sort first, that's the key move.” The rest of the author's notes on Software Engineer interview at Amazon, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“I went straight to conditional aggregation with CASE inside MIN and MAX, which was the right call.” The rest of the author's notes on Data Scientist interview at Amazon, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.

“I had a story ready but it felt thin once I started telling it.” The rest of the author's notes on Software Engineer interview at Amazon, Onsite - Behavioral / Leadership round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.