Shor's SG Collection - 3 Star (0/900)

Shor the Duck's SG Collection, a curated problemset split into difficulties of the best problems on Codebreaker set by the SG IO Community! Criteria for 3 star: Requires some simple application of some basic technique/data-structure, or thinking that may be non-obvious to beginners. (Binary search, (not including BSTA), Prefix Sums, Linear DS, Two Pointer) Should remain suitable for Codeforces pupils that have learnt the basic content.