This course will introduce you to the fundamental ideas in computing

這門課將向你介紹計算的基本觀念

and teach you to read and write your own computer programs.

教你如何讀寫你自己的電腦程式

We are going to do that in the context of building a web search engine.

我們要透過建立網路搜尋引擎的來龍去脈，來進行講解

I'm guessing everyone here has at least used a search engine before.

我猜想這裡的每個人至少曾用過一種搜尋引擎

Like Google, DuckDuckGo or even my personal favorite - DaveDaveFind.

像是 Google、 DuckDuckGo， 或是我個人最喜歡的 DaveDaveFind

You type in what you are looking for, and voila -

當你敲入要搜尋的內容，瞧

in literally a blink of an eye, about a tenth of a second, back come the results.

幾乎一眨眼的功夫，大概十分之一秒，就得到了結果

This might not be enough to make you wise, but it is pretty amazing.

這可能不足以讓你變聰明，但真的很神奇

A goal of this class is to turn some of the magic of the search engine

這門課的目的就是要將神奇的搜尋引擎

into something a bit more understandable.

變得更容易理解

Our biggest goal tho is to learn about computer science.

我們的最主要目標是學習電腦科學

Computer science is about how to solve problems,

電腦科學是關於如何解決問題

like building a search engine,

像是建立一個搜尋引擎

by breaking them into smaller pieces

將它分解成幾個小部分

and then precisely and mechanically describing a sequence of steps that you can use to solve each piece.

然後準確並機械式地描述，解決每個部分的一連串步驟

And those steps can be executed by a computer.

並由電腦來執行這些步驟

For our search engine the three main pieces are:

我們的搜尋引擎有三個主要部分：

finding data by crawling web pages,

透過爬行網頁來收集資料

building an index to be able to respond quickly to search queries,

建立索引，以便能夠快速地對查詢做出回應

and ranking pages so that we get the best result for a given query.

為網頁排序，對查詢取得最好的結果

In this course we will not get into everything that you need

這門課不會對如何建立像 Google

to build a search engine as powerful as Google,

這麼強大的搜尋引擎做詳細的介紹

but we will cover the main ideas and learn a lot about computer science along the way.

但會涵蓋主要的觀念， 並同時學習大量的電腦科學知識

The first three units will focus on building the web crawler.

前三個單元的重點在於如何建立網頁蜘蛛

We will talk more about that soon.

我們很快地會討論更多這方面的知識

Units 4 and 5 will cover how to respond to queries quickly.

第四和第五單元，將涵蓋如何快速地回應查詢

And unit 6 will get into how to rank results

第六單元會介紹如何為結果排序

and cover the method Google uses to rank pages, that made it so successful.

涵蓋了 Google 所使用的網頁排序方法， 這個方法使得 Google 如此的成功

But first, let's talk about how to build a web crawler

但首先，我們來談談如何建立網頁蜘蛛

that we are going to use to get data for our search engine.

它將為搜尋引擎收集資料