The first cry of Atom

The people who are crazy enough to think thay can change the world, are the ones who do

Dear, O

Hello, nice to meet you. I am a novice software engineer who has worked for about 2 years. An ordinary man. I have no honor, no fame and no wealth. Of course you don’t know who I am. There is no connection between us such as email, facebook and twitter. The reason why I can mate your name and your face is no more than watching on TV. That’s all. So in this time I dare to say that I am not familiar with you completely. Unexpectedly I don’t know who you are in spite of writing this letter. For whom? I would like to tell the reason why I wrote this letter.

letters by liz west on flickr

Patterns About BFS in Competitive Programming

So let’s go back to English from today :)

I solved SRM612 Div1 for practice. This problem is this In this post, I left out the detail of this problem because main topic of this post is pattern of BFS. First I tried to solve this problem with some dynamic programming algorithm. But after trying, I found BFS is sufficient algorithm to solve. So now I rewrote my program as below.

Heart Bleedを読んだ

今日の日本時間13:00頃、OpenSSLに致命的なバグがあることがわかった。全世界で動いているSSLプロセスが影響を受ける。 簡単に言うと、メモリ上にある任意のデータを漏洩する可能性があるバグだ。 このバグはもう2年も前からあったらしいがGoogle Security TeamのNeel Mentaに見つけられたのはつい最近で、パッチがあたったのは十数時間前だ。

Add heartbeat extension bounds check.

基本的にはheartbleed.comに詳細が記載されていて、危険なOpenSSLのバージョン、ディストリビューションが書いてある。 対応方法も書いてある。今回はエンジニアとして、コードを読んでどういうバグだったのか理解してみたかったので書いてみる。



なるほど、みんな地元の人達か。温泉津で過ごす夜は少し僕を戸惑わせた。 旅館に付属していない外湯と呼ばれる湯に入りにきたため、地元の人達の憩いの場にお邪魔してしまったようだ。

「じゃ、お先です」 「おやすみなさい」

そんなやりとりをして、みんな湯を上がっていく。僕はというとまだ湯につま先さえつけていない。何しろアツいのだ。 よくよく見てみるとみんな10秒くらいで出たり入ったりじゃないか。とりあえず入ってみるか。

少し鉄の味が残るアツい湯は体にいいらしいが、僕の頭にも強い刺激を与えたようだ。 この二、三日もやもやしていた気持ちが露わになってきた。


久しぶりに日本語で書いてみる。 言葉のリズムが日本語でないと掴めない箇所があるので、やっぱり自分の母国語は日本語なんだとつくづく感じた。 言葉のリズムというのはなかなか掴みづらくて、僕の中では「つい口ずさんでみたくなる言葉」が最もリズムのいい言葉だと思っている。一昔前でいうと『声に出して読みたい日本語』なんていうのが流行ったけれど、あれに近いかもしれない。ただ僕の感覚はもっと俗っぽくて巷で流れているくだらないCMソングなんかはわかりやすい「つい口ずさんでみたくなる言葉」なんじゃないかと。


Next Tile on Tempai

I tried this problem.

Your program receives the hand of mahjong. Returns the “Waiting style” of this hand. But there are some conditions as below.

  • There are no Jihai, only Manzu
  • Make Juntsu, Kohtsu and Head
  • Regard different order waiting as the same
  • If there are no waiting, no output

Marble Problem

I tried this problem.


There are boxes infinitely in a straight line. Each box is labeled from left side …,-2,-1,0,1,2,… to the right side. Now R red marbles are in the -100th box. In the same way, G green mables are in the 0th box and B blue mables are in the 100th box. There no other marbles in all boxes. All boxes should have one marble at most. Repeat below process and make the number of marbles of each each at most one.

  • Select one marble, move it left box or right box.
  • However one box must not have more than two marbles that has different colors each other

Calculate minimum required steps.

SRM144 Div1

After a long time, I returned to TopCoder. I forgot to write algorithm for programming contest such as TopCoder. But previously I realized that it is so important for me to write accurate and fast algorithm within finite time. In order to improve my programming skill again, I returned back to the TopCoder.

Forget Grief, Keep Data

Three years ago, I walked around Shinjuku at Tokyo. I had not yet obtained informal decision from current company for which I now work. So I walked around Shinjuku for job hunting as pre-graduate student called “Shukatsu-sei” in Japanese.

First I wondered what happened. Then I escaped from the building shook violently. In spite of the pleasant friday always, those who were enjoying before the weekend were not the same to the ones of ordinary day. 2011 Tōhoku earthquake and tsunami struck Japan, my homeland.

Difference Between PCA and dA

Today I gave a presentation about Deep Learning in my office. Through this presentation, I felt the difficulty of explanation about mathematic notion without equations. Complex concept should be attached with some equations. Simplicity was one of the biggest purpose of my presentaion.

Anyway, there is a question I cannot answer clearly.

What’s the difference between PCA and Denoised Autoencoder?

It was a difficult question for me. So I studied what distinguished PCA and dA primaly.