「情報処理」最新号の秋葉先生の記事について

先週届いた情報処理学会の学会誌「情報処理」に「プログラミングコンテストチャレンジブック」や「世界で闘うプログラミング力を鍛える150問」の秋葉先生の記事が載っていました。

FOJ有奖月赛-2011年11月 Report

Because I knew this contest for the first time, I participated just a little. It is three to have challenged. I do not understand problems of Chinese well.

1: I guessed from translation with the computer and Chinese which I can understand, a sample case and submitted it. It is an extremely simple problem.

 5: I am in time if I search after having sorted it. However ,it's TLE. I should use binary search. I want to find some good algorithm.

9: I thought this problem was the simplest although it was the very last. You should only think about the binary scale.

Problems are here.
Standings=120,Accept=2,Penalty=71.

Google Code Jam Japan 2011(final) report

I joined final round!

I read B first, and I think I can solve this. So, I begin to think the algorithm without reading other problems! It's big miss!

About 1:30, I can't solve B, so I read A. It's easy. So, I solve A about 30 minute. I should read A first and solve A first!

Then, I think about B, however, I can't solve.

After contest, I watch the explanation, B's algorithm is correct. So, my source has bug.

Result:Score=15/150,Rank=306. Problems are here.

Google Code Jam Japan 2011(Qual) report

I joined Google Code Jam Japan. This contest is first time!

I read all problems, and I solved C first. Binary operation problem. I missed such problem at Google Code Jam 2011, so I revenge this!I submitted small at 44:59, and large at 45:59.

I was too hungry after solving C. So, I go lunch. I spent about 1.5 hours.

Next, I challenge problem B. When I was eating lunch, I think this problem's algorithm, and I get one. So, I could solve it. I think, it's greedy. I submitted small at 2:46:18, large at 2:47:04.

Then, I wanted to submit all problems. So, I challenge problem A. I made a recursion, so I can solve this a little easily. I submitted small at 3:37:57, large at 3:34:44.

Result, Perfect score!
Score:54/54,Rank:86/918.
Problems are here.(Japanese)

Only Source(ソースだけ)

This article is Only Source! I'm too busy now, so I can't write report.
本記事はソースのみです。忙しくて、レポートを書いている暇がないのでご了承ください。

There are sources which I made at the next contest.
次のコンテストで作成したソースです。

・Codechef September Long/Short
・Codeforces #87 (Div.2) / #88
・Topcoder SRM 518(Div.2)
・UVa The Seventh Hunan Collegiate Programming Contest Semilive
・UAPC 7th

Supercon2011 Report

I took part in Supercon2011 with my juniors. However, I'm not high school student, I join only qualification round. We can solve problems in three weeks, but we too busy to solve all of them. So, we solve Problem-A & Problem-B.

The problem is here(Japanese).

In short,it was the shortest road problem. If we use Dijkstra method, the problems can be solved. So I feel not difficult. If we have more time, I'll think Problem-C and better algorithms. It's regrettable.