Hello ! I created a contest in a2oj. Here is the link https://a2oj.com/contest?ID=27599. The contest is gonna last many days(10+) with the purpose to practise in advanced graph/tree algorithms. Some of these algorithms are HLD, Centroid Decomp, Max flow, SCC, and other similar to graph/trees. I have already add some problems and you can register and start practising, but you are kindly request to send me problems via message or post them below, so I can add them in the contest. Problems that you already solved or no, it doesnt matter. In that way, each member will give a problem that maybe an other member hasnt solve it yet, so we can gather many problems to practise.
Thank you !!!