Question

假设我有一个像这样的数组，

The, Quick, Brown, Fox, Jumps

我需要将其中一个元素移动/移动到前面，所以看起来像这样

Brown, Fox, Jumps, The, Quick

如何将数组排序为旋转门？通过移动一个元素并让其余元素落后？

是否有简单的方法或我应该复制/循环/切片/复制？

Answer 1

尝试以下方法

public void ShiftRevolvingDoor(ArrayList list, int count) {
  while ( count > 0 ) {
    ShiftRevolvingDoor(list);
    count--;
  }
}

public void ShiftRevolvingDoor(ArrayList list) {
  if ( list.Count < 2 ) {
    return;
  }
  int lastIndex = list.Count - 1;
  object first = list[0];
  for ( i = 0; i < lastIndex; i++) {
    list[i] = list[i+1];
  }
  list[lastIndex] = first;
}

Answer 2

ArrayList list = new ArrayList();
list.Add("The");
list.Add("Quick");
list.Add("Brown");
list.Add("Fox");
list.Add("Jumps");

ArrayList newList = new ArrayList();
int index = 2;
for (int i = index; i < list.Count; i++)
{
    newList.Add(list[i]);
}

for (int i = 0; i < index; i++)
{
    newList.Add(list[i]);
}

list = newList;

Answer 3

请参阅此How to shift the start of an array in C#?或

        string[] myArray = { "The", "Quick", "Brown", "Fox", "Jumps" };
        myArray = myArray.SkipWhile(t => t != "Brown").Concat(myArray.TakeWhile(t => t != "Brown")).ToArray();

Answer 4

您可以使用Array.Copy来避免编写显式循环。以下代码创建一个新数组，而不是修改原始数组：

T[] rotate<T>(T[] a, int index)
{
    T[] result = new T[a.Length];
    Array.Copy(a, index, result, 0, a.Length - index);
    Array.Copy(a, 0, result, a.Length - index, index);
    return result;
}

public void Run()
{
    string[] words = { "The", "Quick", "Brown", "Fox", "Jumps" };
    string[] result = rotate(words, 2);
    foreach (string word in result)
    {
        Console.WriteLine(word);
    }
}

在保持C＃顺序的同时将ArrayList的元素移动到Front

4 个答案: