Hey guys, although i did not give contest on codeforces but i know my level, my rating is around 1550-1570, i m estimating this based on the contests i given on codechef and spoj problems i solved. I m stating these statistic because i want to know what to do futher to improve my level, i can solve basic adhoc, dp, dfs problems but i do not know data structure like BIT, segment tree etc and i do not get many time to practice because of my job(i deliver pizza for a living). So i wanted to know how can i progress, anyone with a specific training method or specific set of problems is welcome to comment...Best comments, i will deliver pizza.

Hey amigos, I cannot understand the problem behind my recursion for the question BOTTLES (http://mirror.codeforces.com/problemset/problem/730/J) and here is my code(http://mirror.codeforces.com/contest/730/submission/23522054), i have try to do a simple recursion, but i cannot understand why i get wrong answer at tet 7. Plz help guys.

However hard i try i m unable to get the logic behind this problem of goodbye 2016 contest plz help somebody..

hey codeforcers, i decided to do something new and decide to learn python so i need some help here. How can i use an equivalent to c++ set stl in python and similarly how can i use an equivalent to c++ map stl , the dict and set() are not sorted, plz help me.It would be great if someone could provide a usful link or something so that i can learn those things.

Since i am relatively new to competetive programming, it would really help if someone cou;d guide me to some tutorial on matrices which are used in competetive programming like for matrix multiplication, exponentiation, using matrices to solve fibonacci generation problem etc, Plz help!!

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!!

Hello guys , i just started doing segment tree and BIT, could someone plz tell questions on these topics on codeforces in increasing order of difficulty and what is the difference between the two (in terms of their operations), when should i use a segment tree and when should i use a BIT i.e. how should i choose between the two on theBIT basis of various questions ?