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Another famous ancient piece is the "Law Code of Hammurabi, King of Babylon."
VOA: special.2010.06.23
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Suppose I want to do little piece of code that's going to do planar geometry, points in the plane.
好，因此我需要一些,把这些东西收集到，一起的一些方式。
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So I'm going to comment those out, and let's go down to this piece of code, and uncomment it.
那么我会把这些注释上，让我们看看这段代码，取消注释。
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So I've got one more piece of bad code on this point and this is buggy five dot c. So as a comment on top bug of this file challenges, what is, in fact, the bug.
所以我在这里得到了一块很烂的代码,这个是buggy5，c，所以作为这个文件顶端的注释,那实际上是那个。
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Right now, I have to take that piece of code and replicate it everywhere I want in my larger file.
现在我要把这段代码,复制到,大文件中的各个部分。
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All right, you can see that this little piece of code, it's got a loop in there, and what's it doing?
好，你们看到的这一小块代码,是做了一个循环吧？,他在做什么？
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And they're awfully simple because, all I can do now, is decide whether to execute some piece of code or another.
它们之所以太简单的原因是：,现在我能做的，就是,决定执行一块代码或者执行另外一块。
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We want to write a piece of code that helps these guys out, so I'm going to show you an example.
通过写一段代码,来解决一个这样的问题，接下来让我们来看个例子。
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Up on the screen, I've got-- I commented it out, but I've got a piece of code that you've seen before, right up here. OK?
我现在在大屏幕上标出来的,是你们以前看过的一段代码,就在这儿？
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Well I ought to be able to do that by simply generalizing the loop. And that's what the next piece of code on your a hand out shows you.
好的通过生成这个循环,我应该能够达到目的,这也是你们的讲义中下一段代码。
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This seems a little weird, but bear with me for second, in fact, I've given you a little piece a code to do it, which is the next piece of code on the hand out.
这看起来有点奇怪，但是先听我说，实际上我给了你们一段做这件事的代码，就是发给你们的纸张的下一段。
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And the second thing that we talked about is this idea that we want you to in fact learn how to relate a choice you make about a piece of code to what the efficiency is going to be.
关于这个方法第二件事,就是我们实际上希望,你在写代码的时候,能做出优化效率的选择,因为此。
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All right. What does this piece of code say?
好，这段代码什么意思呢？
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This is actually a piece of code that is really easy to think about recursively and is much more difficult to think about in other ways.
这确实是一段用递归思考起来非常容易,而其它方法特别麻烦的代码,这一段代码的意思就是。
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OK. All right, let me show you one other tool that I want to use. Which is, I've written that piece of code, I ought to check it. Well, I could just run it, but another useful thing to do is, I'm, especially as I want to debug these things, is to simulate that code.
好，那么，让我给大家讲下,我想用的另外一个工具吧,也就是，我已经写好了这一块代码，我应该去检查检查,那么我可以去运行它,但是特别是当我想要调试代码的时候。
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Again, imagine if I'm a writing a piece of code.
请再次想象一下我正在编写一段代码。
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OK. So that's what this piece of code does here.
我先设置一个变量。
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So this first little piece of code right here says, ok you give me 2 points, I'll create another 1 of these lists and I'll simply take the x, sorry I shouldn't say x, I'm going to assume it's the x, the x-values are the two points, add them together, just right there, the y-values, add them together and return that list.
好，为了来认识到这一点,让我们来看一个简单的小例子，在你们的课堂手册上，你可以看到我写了一个小程序,它假设我得到了，这些点中的一些，我想对它们做一些操作，例如我想把它们加到一起，那么这里的第一小片，代码的意思是，好给我两个点，我会再创建一个数组。
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Computing square root. I'm going to capture it in a piece of code, I'm going to be able to refer to it by a name, and I'm going to suppress the details, meaning inside of that computation, you don't need to know what it does. You just need to know, if I give it the right kind of input, it'll give me back an input that satisfies the contract that I set up.
比如计算平方根,我会用一段代码来说明,我将给它命名,并且忽略细节,意思就是在这一段计算过程中,你不用知道它做了什么，你只需知道，如果我进行了正确的输入,它将会给我符合条件的输出。
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I'm given an integer that's a perfect square, and I want to write a little piece of code that's going to find the square root of it. All right so I'm cheating a little, I know it's a perfect square, somebody's given it to me, we'll come back in a second to generalizing it, so what would the steps be that I'd use to walk through it?
完美平方数的整数，我想写一段代码来求这个数的平方根,好，我这儿有点儿作弊了,我知道这是一个完美的平方数了,他们给我的，我们后面会讲怎么产生这个数的，那么我想解决这个问题,需要什么步骤呢？
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to do sqrt, or square root-- no, I'm going to square root use sqrt, that's the name I'm using here-- square root a hundred different places in some piece of code. Without function, I'd have to copy that piece of code everywhere.
让我做一下准备,想象一下我要调用sqrt或者-,不，我会调用sqrt函数,这是我在这里用的名字，我得把这段代码到处复制。
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Remember last time, we wrote this simple piece of code to print out even or odd. If, you know, x, 1 it was in fact, even or odd. So let me show you what a flow chart for that would look like, because I want to make a comparison point here.
这就像这里有一些脚蹼一样,首先进行测试，然后把球这样放来让ANS加,然后回来继续测试，最终跳出循环然后打印答案。
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All right. If you flip to the second side of your handout, you'll see that I have a piece of code there, that does this-- let me, ah, I didn't want to do that, let me back up slightly- this is the algorithm called search.
你可以看到实现这个功能的代码,让我，额，我不想这么做,让我们回来一点,这就是命名为search的算法-,我们来看看这个算法吧。
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Why is this much nice? Well, that's a handy piece of code. Because imagine I've got that now, and I can now store that away in some file name, input dot p y, and import into every one of my procedure functions, pardon me, my files of procedures, because it's a standard way of now giving me the input.
为什么这样很好呢？,这是一段很好用的代码,因为想象下如果我有了这段代码,我能把它用某个文件名保存起来,后缀是。py，导入到所有的处理函数中,抱歉，我的处理文件,因为这是一个标准的输入方法。
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First of all, two parameters. It's OK. All it says is, when I call this, I need to pass in two parameters for this to work. All right? Now, if I want to use that, I'm going to use a second piece of code here, called Barnyard. I'm going Barnyard to read in a couple of values, convert them into integers, and then I'm going to use solve to get a solution out.
注意我得到了什么,第一，两个参数,它的意思就是我调用这个函数，我得给它输入两个参数，明白了吗？,现在如果我要使用它我得用,这里的第二段代码，也叫,我将读入一组值，将它们转化为整型,然后我会用solve得到一个解决方案。
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And we hope that at the end of the class, every time you're confronted with some technical problem, one of your first instincts is going to be, "How do I write the piece of code that's going to help me solve that?"
并且我们希望到了期末，每当你要面对一些,技术问题的时候，你们的本能之一将会是：,“我怎么才能编写一个代码,来帮我解决这问题？“
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OK, let me comment this out, and let's look at this next little piece of code. All right.
好，让我添加一点注释，然后让我们看看,下面的一些代码，好。
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Right, so here's a little piece of code that's going to print out the smallest value of three.
好，那么这一小段代码,就是会显示出,三个值中最小的来。
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With simple branching, how long is it going to take to run a piece of code?
但是在简单分支程序中，执行一个程序,要多长时间呢？
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Right, and just to get a sense of this, let's look at a simple little example, so on your hand-out, you'll see I've got a little piece of code that says assuming I've got one of these points, I want to do things with it, for example I might want to add them together.
这些数组中的一个，你怎么能够知道，它是哪种类型的呢？,你怎么知道它是以笛卡尔坐标,表示的还是以极坐标,形式表示的呢？,你没有可以用来区分的东西，你没有说明这种信息,聚集实际上的意义。
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