December 2016
Intermediate to advanced
440 pages
9h 44m
Japanese
Content preview from アルゴリズムクイックリファレンス 第2版
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390
■
12
章 結び：アルゴリズムの諸原則
12.5
探索を構築せよ
人工知能（
AI
）分野の初期の開拓者の多くの特徴は、いまだ解がわからない問題
を解こうとしていることであった。問題を解く一般的方式は、大規模なグラフの探
索問題に変換するものだった。本書では、この方式にまるまる
1
章を割いたが、そ
れは、これが重要で一般的な技法だからである。ただし、他に代替案がない場合に
だけこれを適用するよう注意することだ。経路探索方式を使って、未整列の配列（初
期節点）から始めて、整列した配列（目標節点）を生成するまでの一連の要素移動を
見つけることもできるが、データ整列には
O(n log n)
のアルゴリズムがたくさんあ
るので、このように指数的な振る舞いをするアルゴリズムは使わない方がよい。
表12-5は、
7
章で論じた経路探索アルゴリズムを示す。すべて指数性能を示すが、
これらが知的なゲーム実行プログラムを実装するのにいまだに選択される方式なの
だ。これらのアルゴリ
ズムは解を見つける構造を示しているが、成功しているのは
高度なヒューリスティック（発見的方式）のおかげである。これによって探索処理が
知的になっている。
表12-5 7章のAIにおける経路探索
アルゴリズム 最良 平均 最悪 概念 該当する節
深さ優先探索
b*d b
d
b
d
スタック、集合、後戻り 「7.7 深さ優先探索」
幅優先探索
b
d
b
d
b
d
キュー、集合 「7.8 幅優先探索」
A*
探索
b*d b
d
b
d
優先度付きキュー、集合、
ヒューリスティック
「7.9 A* ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.