### Theo830's blog

By Theo830, history, 11 days ago,

I really need help to debug my code for JBOI 2012 Squares. I got 18/20 in mendo but I really can't find the bug this is my code (code) at the end of the code there is one of the test cases that fails. Can someone help me?

• +3

By Theo830, history, 6 months ago,

I found a cheater in yesterday's round. He/She was a tester and he/she submitted from another account.

I am not 100% sure but the coding style + template is exactly the same. Also, the submissions of the account are really fast for a low CM and his submission on problem C is very weird(105687315).

Please MikeMirzayanov check this out.

• +392

By Theo830, history, 7 months ago,

Problem: You have some sets and you want to check if set $B$ is subset of set $A$. You can erase or insert any element from any set. Let's say that $Q$ is the number of queries (check,insert or erase) and $Q <= 10^5$.

I think that may exist a solution using hash function. If you find the binary representation of all the sets (a bit is true only if it exists in the set) if there is a way to find the bitwise AND operation of two hash numbers then if $A$ & $B$ $=$ $B$ then $B$ is subset of $A$.

Any ideas about a solution?

• +9

By Theo830, history, 7 months ago,

Codeforces recently added dates from the past contest at your contests page or in your rating graph!

• +334

By Theo830, history, 12 months ago,

Today when I was looking at the submissions in problem 1381B - Unmerge I saw 300iq's and Benq's solution. Both submissions(87538626 , 87530540) has a for loop and it does some operations with a bitset in order to find if you can make the sum of some sizes of blocks equal to n. I have done the same solution however I use simple $dp[i][j]$ = if we can make the sum $j$ using only the first $i$ elements. I was wondering what is the time complexity of their dp. Any ideas?

• +3

By Theo830, history, 17 months ago,

Does anyone know a side that I can submit for ejoi 2019?

• +3

By Theo830, history, 22 months ago,

Because tomorrow is the BOI 2019 day 1 I want to ask if someone know if there will be live scoreboard. Thanks a lot.