If you've been grinding LeetCode without a plan, you already know the problem: there are thousands of questions, but only a handful of underlying patterns. Once you recognize the pattern, most "new" problems stop feeling new.
Here are the 7 patterns that keep showing up across interviews at companies of every size — and how to recognize them fast.
Two Pointers
Signal: Sorted array, or you're comparing pairs/windows from both ends.
Classic problems: Pair sum in sorted array, container with most water, remove duplicates in place.
