迭代因子实施 [英] Iterative Factorial Implementation

问题描述

我找到多个迭代解决方案，在网络定义的因子 N 。他们看起来是这样的：

I found multiple iterative solutions in the net for defining the factorial of n. They look something like this:

int Factorial(int number)
{
   int factorial = 1;

   for (int i = 1; i <= number; i++)
      factorial *= i;

   return factorial;
}

不因子（0）= 1 和因子（1）= 1 ？因此，里面的for循环的计数器变量应该从 2 ，因为它下面的一切都将产生 1

Doesn't Factorial(0) = 1 and Factorial(1) = 1? Therefore, the counter variable inside the for loop should start with 2 since everything below it will yield 1.

   for (int i = 2; i <= number; i++)
      factorial *= i;

是否有某种原因，他们所使用的 1 作为起始编号为计数器？

Is there some reason why they used 1 as the starting number for the counter?

推荐答案

没关系 - 1或2将工作，乘以1什么都不做。然而，大多数的循环开始与0或1，而这只是遵循模式。另外，阶乘的定义通常表示为所有的正整数直到n的产物，因此这包括一个。从本质上讲，1，美观，更好的起点。

It doesn't matter - either 1 or 2 will work, as multiplying by 1 does nothing. However, most loops start with 0 or 1, and this just follows the pattern. Also, the definition of factorial is often stated as the product of all positive integers up to n, so this includes one. Essentially, 1 is, aesthetically, a better starting point.

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