c# - 在哈希集字典中查找值的组合

Question

我有一个 Dictionary<string, HashSet<string>>我想遍历并找到 HashSet 中所有可能的组合，而无需任何重复。例如(虚拟数据):

Keys          Values (HashSet)

"greeting"     "Hello" "Hi" "Hey" "Howdy" ...
"Name"         "Tom" "Angel" "Edward" ...
"question"     "how are you?" "can you help me?" "is everything okay?" ...
    ...                  ...
    ...                ....

我希望输出是某种集合，每个值如下:

"Hello Tom how are you?"
"Hello Tom can you help me?"
"Hello Tom is everything okay?"
"Hello Angel how are you?"
"Hello Angel can you help me?"
"Hello Angel is everything okay?"
"Hello Edward how are you?"
...

"Hi Tom how are you?"
"Hi Tom can you help me?"
"Hi Tom is everything okay?"
"Hi Angel how are you?"
...

我希望尽可能抽象到可以在哈希集中添加尽可能多的键和值的位置。

我曾尝试递归执行此操作，但我不太擅长此操作，而且我无法想出一个基本案例...我认为您可以使用 linq 来执行此操作，但我对 linq 一点都不熟悉。

我使用 Dictionary<string, HashSet<string>> 的原因是因为我收集信息的方式，所以我想保留这个数据结构。

谢谢!

Answer 1

鉴于问题中提供的示例数据:

var data = new Dictionary<string, HashSet<string>>
{
    {"greeting", new HashSet<string> {"Hello", "Hi", "Hey", "Howdy"}},
    {"Name", new HashSet<string> {"Tom", "Angel", "Edward"}},
    {"question", new HashSet<string> {"how are you?", "can you help me?", "is everything okay?"}}
};

没有任意键，这里有一个使用 LINQ 的简单方法:

var collection = from g in data["greeting"]
    from n in data["Name"]
    from q in data["question"]
    select string.Format("{0} {1} {2}", g, n, q);

使用 this answer 中的 CartesianProduct 扩展方法看起来像这样:

var collection = data.Select(x => x.Value).CartesianProduct().Select(x => x.Aggregate((a, b) => a + " " + b));

无论哪种情况，这里都是我用来在控​​制台应用程序中显示输出的 foreach:

foreach (var line in collection)
{
    Console.WriteLine(line);
}