c# - 从 C# 中的唯一(独立)元素获取索引

Question

我想获得独立元素的索引。元素本身可能更频繁地出现在列表中(一个接一个或混合出现)。单个元素的指示是前驱和后继不等于当前元素。有没有一种优雅的方法来做到这一点？

示例 :

1.  A
2.  A
3.  A
4.  B
5.  B
6.  A
7.  B
8.  B
9.  C
10. B

结果:

6,9,10

Answer 1

简单地迭代项目并检查该条件

char[] items = { 'A', 'A', 'A', 'B', 'B', 'A', 'B', 'B', 'C', 'B' };
for (int i = 0; i < items.Length; i++)
{
    if (i == 0)
    {
        // in case of the first element you only have to validate against the next
        if (items[i] != items[i + 1])
            Console.WriteLine(i + 1);
    }
    else if (i == items.Length - 1)
    {
        // in case of the last element you only have to validate against the previous       
        if (items[i] != items[i - 1])
            Console.WriteLine(i + 1);
    }
    else
    {
        // validate against previous and next element
        if (items[i] != items[i - 1] && items[i] != items[i + 1])
            Console.WriteLine(i + 1);
    }
}

https://dotnetfiddle.net/kWmqu7