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I want to show you how easy it is to change the code. But, notice, once I've added this I actually have a problem. This is now an under-constrained problem. I have more unknowns than I have equations.
我加上这个条件后,我马上面临一个问题了,这就是现在是一个非约束性问题了,我的未知数比方程数多,你从代数中可以知道。
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I know this is a simple example, but when you mature as a programmer, one of the first things you should do when you sit down to tackle some problem is write something like this pseudo code.
我知道这是个很简单的例子，但是当你们成长为一名程序员后，当你们碰到问题后第一件事情就是,该写一些类似于,伪代码的东西。
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Now in fairness, that particular problem kind of happened because so many companies ended up running so much code for many more years than the programmers actually thought they would be running it, but the idea is still the same.
公平起见，那个问题有时会发生,因为实际上，很多企业在这么多年里运行了,比程序员多得多的代码,虽然他们将运行它，但那个构想还是一样的。
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That creates a problem in the genetic code in that there's 64 possible sequences but there's only 20 some amino acids, so each amino acid can be specified by more than one codon.
这里有个问题,遗传密码有六十四种可能的序列,而只有二十种氨基酸,因此每种氨基酸都有,不止一种密码子与之对应
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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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Right, so the things we want you to take away from this are, get into the habit of using pseudo code when you sit down to start a problem, write out what are the steps.
好，这儿我想大家明白的就是,养成解决问题时先写伪代码的好习惯,把步骤都写出来,我想要告诉你们的是一个好的程序员。
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But I want to stress again, as long as I do the base case right and my inductive or recursive step reduces it to a smaller version of the same problem, the code will in fact converge and give me out an answer.
就开心的去做吧,但是我想再次强调,只要基础事件处理正确而我的递归,或递推步骤能把它简化为更简单的同类问题,那么这段代码就可以收敛。
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Delete those lines of code and move them up to the top and problem solved.
把这几行代码删除，然后把它们放到,前面去，问题就解决了。
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And in particular, if I think about that problem - actually I want to do this- if I think about that problem, I'm going to write a little piece of pseudo code.
关于这个问题尤其要注意的是,实际上当我考虑这个-,问题的时候我想这么做，我会去写一点伪代码。
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I stress it in particular because I know you're all going to get into this stage; you've got a problem set due in a couple of hours, you're still writing the code, you don't want to waste time, and I'm going to use quotes on "waste time", doing those extra things to do the defensive programming, you just want to get the darn thing done.
我特别强调了这一点,因为我知道你们都会慢慢成为程序员;,你在写代码过程中造成了一系列的错误，你还在写代码，你不想浪费时间，我想把“浪费时间“用引号圈起来，浪费时间来做因为防卫性程序设计，而带来的这些额外的事情,你只想赶紧把程序写完，这不是一个好习惯，因为当你做完回头。
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Spelling. These are just dumb little things to look for. Did you spell all the identifiers the way you think you did. The problem is, when you read code you see what you expect to see.
拼写错误，你可能得找找这些粗心的小错误,你是否拼对了标识符,问题是当你阅读代码的时候,你看到的都是你以为的。
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I've certainly written code that has this problem, I've tried to use my own code that has this problem, and good to us, right, good hygiene, I'm going to use that word again here, of getting into the habit of writing defensive code up front, it's part of that collection of things that you ought to do is a great thing to do.
我举手了吧？,我当然写过犯这种错误的程序了,我也尝试过应用含有这种错误的代码，不错，好的卫生，我还是要用这个词,对我们有帮助，养成写防卫性,代码的好习惯，是你应该做的,一系列事情之一,也是我们日后要做的主要的事情。
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