在哈希集字典中查找值的组合

Question

我有一个Dictionary<string, HashSet<string>>，我想通过它找到 HashSet 中所有可能的组合，而不需要任何重复。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，每个值都为：

"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?"
...

我希望这个尽可能抽象，以便我可以在哈希集中添加任意数量的键和值。

我曾尝试以递归方式执行此操作，但我对此并不太擅长，我无法提出基本情况...我认为您可以使用 linq 执行此操作，但我对 linq 一点也不熟悉。

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 扩展方法如下所示：

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);
}

Answer 2

一个简单的解决方案是......

Dictionary<string, HashSet<string>> test = new Dictionary<string, HashSet<string>>();
        test.Keys.ToList().ForEach(key =>
        {
            test[key].ToList().ForEach(value => Console.WriteLine("key key:" + "value:" + value));
        });