Skip to main content

Posts

Featured

Notes on problems other than Codeforces - May 2019

Probe Droids - NAIPC 2018:
The differences of the slopes between lattice points (x, y <= 1e6) can be as small as 1e-12. We can descend along Stern-Brocot Tree to find the closest fraction to a floating point number. Euclidean-like method to find the number of lattice points under a certain line. 
F - Unhappy Hacking - AtCoder ARC 59 Tried to make observation of the DP formula but failed to improve an O(N^3) solution It turns out that the content of the string does not matter. Then we can just calculate the number ways to get a string length of m after n operations and divide it by 2^n since the diferent strings are essentially the same.  More problems to add....

Latest Posts

Codeforces Problem Notes: Starting from 2019.4.26

A2OJ Ladder Climbing Note (1900 <= Codeforces Rating <= 1999)

Personal Thoughts after Codeforces Round #477 (rated, Div. 2, based on VK Cup 2018 Round 3)

Divide by Zero 2018 and Codeforces Round #474

Thoughts on Hello 2018. For myself.

Use of Linked List and Priority Queue in CF Round 452, Problem E

"Meet-in-the-middle technique" on Educational Codeforces Round 32, Problem E

''Euler tour technique' and 'Lazy Segment Tree' based on CF 877E