Question

我正在使用Knuth-Fisher-Yates算法在Windows窗体上显示一个混洗的字符串项数组。我没有得到任何重复，这是我试图实现的，但是，它只吐出数组的13个元素中的12个。如何让它显示数组的所有13个元素？这是我的代码：

private void FormBlue1_Load(object sender, EventArgs e)
{
// set the forms borderstyle
this.FormBorderStyle = FormBorderStyle.Fixed3D;

// create array of stationOneParts to display on form
string[] stationOneParts = new string[13];
stationOneParts[0] = "20-packing";
stationOneParts[1] = "5269-stempad";
stationOneParts[2] = "5112-freeze plug";
stationOneParts[3] = "2644-o'ring";
stationOneParts[4] = "5347-stem";
stationOneParts[5] = "4350-top packing";
stationOneParts[6] = "5084-3n1 body";
stationOneParts[7] = "4472-packing washer";
stationOneParts[8] = "3744-vr valve o'ring";
stationOneParts[9] = "2061-packing spring";
stationOneParts[10] = "2037-packing nut";
stationOneParts[11] = "2015-latch ring";
stationOneParts[12] = "stem assembly";

Random parts = new Random();

// loop through stationOneParts using a Swap method to shuffle
labelBlueOne.Text = "\n";
for (int i = stationOneParts.Length - 1; i > 0; i--)
{
int j = parts.Next(i + 1);
Swap(ref stationOneParts[i], ref stationOneParts[j]);

// display in a random order
labelBlueOne.Text += stationOneParts[i] + "\n";
}
}

private void Swap(ref string firstElement, ref string secondElement)
{
string temp = firstElement;
firstElement = secondElement;
secondElement = temp;
}

Answer 1

您无法访问第一个元素。 for（int i = stationOneParts.Length - 1; i＆gt; = 0; i - ）。

Answer 2

当您使用交换项目的循环显示文本时，您将不会显示最后一项，因为它永远不会自行交换。

只显示循环后的最后一项：

labelBlueOne.Text += stationOneParts[0] + "\n";

或者，您可以显示循环之外的所有项目：

for (int i = stationOneParts.Length - 1; i > 0; i--) {
  Swap(ref stationOneParts[i], ref stationOneParts[parts.Next(i + 1)]);
}
labelBlueOne.Text = "\n" + String.Join("\n", stationOneParts);

Answer 3

将循环条件更改为i >= 0。

Answer 4

最简单的方法：

        Random rnd = new Random();
        var stationOneParts = new List<string>{
        "20-packing",
        "5269-stempad",
        "5112-freeze plug",
        "2644-o'ring",
        "5347-stem",
        "4350-top packing",
        "5084-3n1 body",
        "4472-packing washer",
        "3744-vr valve o'ring",
        "2061-packing spring",
        "2037-packing nut",
        "2015-latch ring",
        "stem assembly"}.OrderBy(s => rnd.Next());

        labelBlueOne.Text = string.Join(Environment.NewLine, stationOneParts);

Answer 5

既然你提到C＃4.0，为什么不写C＃-ish？

using System.Linq;

// ...

    var stationOneParts = new [] { "20-packing",
        "5269-stempad",
        "5112-freeze plug",
        "2644-o'ring",
        "5347-stem",
        "4350-top packing",
        "5084-3n1 body",
        "4472-packing washer",
        "3744-vr valve o'ring",
        "2061-packing spring",
        "2037-packing nut",
        "2015-latch ring",
        "stem assembly" };

    Random rand = new Random();
    stationOneParts = stationOneParts
        .Distinct() // see subject: '... without duplicates'
        .Select(i => new { i, key=rand.Next() })
        .OrderBy(p => p.key)
        .Select(p => p.i)
        .ToArray();

随机字符串数组没有重复

5 个答案: