view the contest at codeforces group
tasks: tree, A-K query, suitable weights
author's comment: Kudos to Warinchai and ttamx who found better solutions for C, running in O(n^1.5) and O(n lgn) respectively; the official solution runs in O(n^1.5 lgn)
SheepDev aims to help students practice competitive programming per holding public contests.
the contests aim to be fun and educational.
my discord is sleepntsheep
my email is apinyanonp [at] gmail [dot] com