November 2017
Beginner to intermediate
344 pages
7h 2m
Chinese
Content preview from 深入理解運算原理｜從簡單的機器到無所不能的程式
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終極機器
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這很讓人興奮，因為它使得圖靈機的最大運算能力可以用在單一的可程式化裝置。我們
可以將軟體（編碼過的圖靈機描述）寫入磁帶，再將那個磁帶供給 UTM，並執行我們
的軟體來產生我們想要的行為。有限自動機和下推自動機無法以這種方式模擬它們自己
的類型，所以圖靈機影響了運算機器從有限到強大、從專用裝置到完全可程式化裝置等
兩種轉變的過程。
讓我們簡單看一下 UTM 的運作方式。實際建置 UTM 涉及許多繁瑣和無趣的技術細
節，所以我們的探索相對來說將僅止於表面，但我們至少應該能說服自己這樣的事情的
確可能。
編碼
在我們可以設計 UTM 的規則手冊之前，必須決定如何將整個圖靈機表示成磁帶上的一
組字元。UTM 必須讀取規則、接受狀態、任意的圖靈機起始組態，然後隨著模擬物的
進展，重複更新模擬機的目前組態，所以我們需要 UTM 可以運作的實用方式來儲存這
所有的資訊。
其中一項挑戰是每個圖靈機可以存入它磁帶的狀態和不同字元的數量都有限，而這兩個
數量都是以其規則手冊預先固定設置，UTM 也不例外。如果我們想要設計可以處理 10
個不同磁帶字元的 UTM，它該如何模擬其規則使用 11 個字元的機器？如果我們更慷
慨，想要設計它來處理 100 個不同的字元，當我們想要模擬使用 1000 個字元的機器會
有何結果？不過，我們決定用在 UTM 自己磁帶的諸多字元，卻永遠不足以直接表示每
種可能的圖靈機。
模擬機器和 UTM 之間還存有無心的字元衝突風險。要在磁帶儲存圖靈機規則和組態，
我們需要能夠使用對 UTM ...
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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.