Question

所以我的教授希望我们制作一个程序，其中包含一个数字而不是吐出平方根。问题是我们不允许使用Math.Sqrt，否则会有50％的分数惩罚。因此，我使用here ...

中的以下方法

为sqrt猜一个数字。
将数字除以猜测。
平均原始猜测和新猜测。
将此平均值设为当前猜测值，然后恢复为第2步。

一旦你这样做了3-4次（或更多？），它应该越来越近，越接近实际的sqrt。

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void calculateSqr_Click(object sender, RoutedEventArgs e)
    {
        decimal wantedSqrt = Decimal.Parse(input.Text); //Takes the number from the textbox, and converts it to an int.
        Random rnd = new Random(); //We're going to pick a random number.
        decimal guess = rnd.Next(1, 100); //Pick a number between 1-100.

        for (int i = 0; i <10; i++)
        {
            decimal divHolder = wantedSqrt / guess; //Divide.
            decimal avgVal = (guess + divHolder) / 2; //Average.
            avgVal = guess; //Make the average our new guess.

            Console.WriteLine(guess); //Seems like all it does is write the number 10 times.
        }
        string wantedSqrtString = wantedSqrt.ToString();
        MessageBox.Show(wantedSqrtString);
    }
}

正如您所知，问题出在我的for循环中。我认为它会起作用，它需要想要的Sqrt，潜水它，用猜测平均它，然后新的平均值将成为猜测，它会循环。相反，它只是在输出中重复10次。这里出了什么问题？

Answer 1

我在这里修改了你的代码：

    decimal wantedSqrt = Decimal.Parse(input.text); //Takes the number from the textbox, and converts it to an int.
    Random rnd = new Random(); //We're going to pick a random number.
    decimal guess = rnd.Next(1, 100); //Pick a number between 1-100.

    for (int i = 0; i <10; i++)
    {
    decimal divHolder = wantedSqrt / guess; //Divide.
     guess = (guess + divHolder) / 2; //Average.
     //Make the average our new guess.

    Console.WriteLine(guess); //Seems like all it does is write the number 10 times.
    }
    string wantedSqrtString = wantedSqrt.ToString();
    Console.WriteLine(wantedSqrtString);

无法使用Math.Sqrt进行循环以获得准确的平均值。想法？

1 个答案: