AtCoder Grand Contest 007 review

Link AGC 007 top page Editorial I felt you need more invetiveness/creativeness in this contest, and it was difficult.  A – Shik and Stone Problem Compared to ARC (regular contest), it is slightly difficult even from problem A. The most elegant solution is to just check the number of ‘#’ is equal to \(W+H-1\) or not as explained in Editorial. However, I could not notice it so I checked that we can actually go using only right or down or not.

  B – Construct Sequences Problem You need to come up with one construction method which satisfies the 3 conditions. Editorial way is much more easier than below […]

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AtCoder Regular Contest 063 review

Link ARC 063 top page Editorial C – 一次元リバーシ / 1D Reversi Problem  

D – 高橋君と見えざる手 / An Invisible Hand Problem I didn’t notice that there is a restriction that each \(A_i \) is different. So it took time for implementation.

  E – 木と整数 / Integers on a Tree Problem Follow editorial.


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Codeforces Round #378 Div. 2 review

Link Codeforces Round #378 Div. 2 (Contest 733) A. Grasshopper And the String Link: Problem Category: Implementation Even this is a first problem, I get wrong answer for first time submission. It is necessary to consider a corner case at the “end of the text”. Some other solution is inserting extra ‘A’ at the end of text so that you can handle it in the same way. (ex. latte0119’s solution)  

B. Parade Link: Problem Category: math Below implementation is a little bit optimized solution for not to use memory of \(O(N)\), but use \( O(1) \). But in the contest, it is better to consider solve it as fast as possible rather […]

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