随机插入，随机获取C＃集合

Question

I need a C# collection from which I can as quickly as possible pick out a random element, but also add new elements to. It is for a scrabble bag of letter blocks. Which one should I use?

Answer 1

You can use List<T> . It depends what you want to keep in that list too.

Answer 2

Anything implementing IList (or, more probably IList<T> ) as these can be referenced by index. Its very easy to pick a random number in the range 0 < n < list.Count-1 and get that item from the list.

eg/

// assumes 'random' is an instance of System.Random
myRandomElement = myList[random.Next(0,myList.Count-1)]

Answer 3

Dictionary

The Dictionary generic class provides a mapping from a set of keys to a set of values. Each addition to the dictionary consists of a value and its associated key. Retrieving a value by using its key is very fast, close to O(1) , because the Dictionary class is implemented as a hash table.

Edit: Ok, I thought you need to specify keys or something.

What is wrong with List<> ?

Answer 4

如果您想提高速度，我建议您使用Dictionairy