And I'm going to show you an example in a 1 second, just to drive this home, but notice the characteristics. In the first two cases, the problem reduced by 1 at each step.
在前面两个例子里,每一部问题的规模缩小了,不管是迭代的还是递归的,这表明这个问题的复杂性可能是线性的。
We're going to see variations of this, we're going to see a variation of it called recursion, a little later on, but for now we're just going to talk about how do we do iterations.
我们稍后会去,看它的变量,它的所谓的递归数的变量,但是现在我得先讲讲,怎么来实现迭代。
We saw some quadratic algorithms, typically those are things with multiple nested loops, or iterative or recursive calls, where you're doing, say, a linear amount of time but you're doing it a linear number of times and so it becomes quadratic, and you'll see other polynomial kinds of algorithms.
我们看过一些平方算法,他们一般进行了多次嵌套循环,或者递归迭代调用,对一个线性操作调用线性次,这样就变成平方次了,以后你们能看到,一些多项式算法。
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