I was solving questions of today's round and as usual I couldn't solve problem D which is tagged tree + DP as i have been always weak in these type of questions so someone plz help!! i would be forever in debt if anyone could suggest from where i can solve these questions, i have already tried almost all questions on codeforces, but for each of them i had to read the editorial if anyone could provide the questions from various online judges similar to today's question, i would be glad, plz HELP !!!! Also if anyone could provide some rich resources to study this topic.I know we need practie to improve in any topic so i m asking for all the questions related to this topic(preferably like today's). Plz help your brother in the name of Allah!!