c#一维数组不同元素个数问题,求个快点的算法

[wanabe]

比如说string[] aa = new string[]{1,2,1,2,1,2}
我要得到的结果是2

[lake_cx]

没排序的不可能快

[jinjazz]

只有循环判断

[changjiangzhibin]

遍历再计数

[zhengren2008]

一般也就是
foreach(string s in aa}
{
int count = 0;
if(s == "2"}
{
count++
}
}

console.writeline(count);

[vrhero]

Dim aa As String() = {1, 2, 1, 2, 1, 2}
Dim x = Aggregate a In aa Select a Distinct Into Count()

最简单的...不幸地是...

1.只有.NET 3.5以上才支持...

2.只有VB才支持...

[bobocici]

刚刚在怀疑，不可能有vb支持而优雅的c＃不支持的道理呢，果然....

        
        static void Main(string[] args)
        {
            string[] temp = new string[] { "aaa", "bbb", "ccc", "aaa", "bbb", "ccc" };
           Console.WriteLine( temp.Distinct<string>().Count<string>());
        }

好像是可以的。

[refeiner]

.NET2.0

public static void Main()
{
int[] EX_Array = {1,2,3,4,3,3,4,3,4,3};
Predicate<int> match = new Predicate<int>(FindMethod<int>);
int[] answers = Array.FindAll(EX_Array, match);
foreach(int answer in answers)
{
Console.WriteLine(answer);
}
Console.ReadLine();
}

public static bool FindMethod<T>(T number) where T:IComparable
{
int result = number.CompareTo(3);
return result == 0;
}