https://hyeseonko.github.io/A minimal, portfolio, sidebar, bootstrap Jekyll theme with responsive web design and focuses on text presentation. 2026-08-20T23:40:57+09:00 Hyeseon Ko https://hyeseonko.github.io/ Jekyll © 2026 Hyeseon Ko /assets/img/favicons/favicon.ico /assets/img/favicons/favicon-96x96.png 2026-08-20T09:00:00+09:00 2026-08-20T09:00:00+09:00 https://hyeseonko.github.io/posts/top-k-frequent-elements-why-eviction-is-safe/ Hyeseon Ko

LC347 Top K Frequent Elements asks for the k most frequent values in an array. The real question The problem splits into two steps, and only one of them is interesting: Count how often each number appears. Pick the top k by count. Step 1 is a Counter. There is nothing to decide. The whole problem is step 2 — and the follow-up note pins down what’s wanted: Your algorithm’s time com...

2026-08-18T09:00:00+09:00 2026-08-18T16:28:24+09:00 https://hyeseonko.github.io/posts/group-anagrams-canonical-keys/ Hyeseon Ko

LC49 Group Anagrams asks you to group words that are permutations of each other. The real question Grouping is trivial once you have the right key: build a dict from key to list, append, done. The entire problem is “what makes two anagrams collide and everything else not?” That’s a canonical form question — pick any representation that is identical for all members of a group and unique across...