Question

我有一个在线研究项目，还有很多选择题。例如...↓

问：您喜欢哪种编程语言？

1,C
2,C++
3,CSharp
4,VB.NET
5,JAVA

我将所选项目保存为1并取消选择为0

所以结果就像↓

People      Selected
people1     00100
people2     11100
people3     00110
people4     00100
people5     NULL
... ...

现在我的问题是如何通过上面的结构使用Linq创建一个像下面这样的单向表？

TOTAL     (N=5)
C          1
C++        1
CSharp     4
VB.NET     1
JAVA       0
NULL       1

这是我的来源，我认为这不好

static void Main(string[] args)
{
   // the mapping...
   Dictionary<int, string> dic = new Dictionary<int, string>()
   {
       {0 , "C"} , 
       {1 , "C++"} , 
       {2 , "CSharp"} , 
       {3 , "VB.NET"} , 
       {4 , "JAVA"}
   };

   // the answer data by the people
   List<string> lstM = new List<string>()
   {
      "00100" , // people1
      "11100" , // people2
      "00110" , // people3
      "00100" , // people4
      "NULL"    // people5
   };

   var result = from p in lstM 
                where "NULL".Equals(p)
                group p by p into g
                select new {Key = g.Key , Cnt = g.Count()};

   foreach (var d in dic)
   {
      var tmp1 = from p in lstM
                 where !"NULL".Equals(p) && "1".Equals(p.Substring(d.Key, 1))
                 select 1;

      Console.WriteLine(string.Format("Key = {0} , Cnt={1}", dic[d.Key], tmp1.Count()));
   }

   foreach (var x in result)
   {
      Console.WriteLine(string.Format("Key = {0} , Cnt={1}", x.Key, x.Cnt));
   }

   Console.ReadKey();
}

请有人能给我一些好主意吗？

感谢您的建议......

Answer 1

dic.Select(a=>
{
    Option = a.Value,
    Count = lstM.Where(o => o.Length > a.Key && o[a.Key] == '1').Count()
});

这会给你：

C          1
C++        1
CSharp     4
VB.NET     1
JAVA       0

Answer 2

丢失所有二进制编码和“字符串输入”。快速举例：

var options = new [] { "C", "C++", "C#", "VB.NET", "Java" };

var people1 = new string[] { "C#" };
var people2 = new string[] { "C", "C++", "C#" };
var people3 = new string[] { "C#", "VB.NET" };
var people4 = new string[] { "C#" };
var people5 = new string[] { };

var pollAnswers = new [] { options, people1, people2, people3, people4, people5 };

pollAnswers.SelectMany(answ => answ).
            GroupBy(opt => opt).
            ToDictionary(gr => gr.Key, gr => gr.Count() -1);

这会为每个被询问的人创建一个选定答案的字典。稍后您可以使用LINQ分组和聚合运算符来生成所需的结果。

C: 1
C++: 1
C#: 4
VB.NET: 1
Java: 0

我使用string类型作为答案选项作为示例，它可以是其他类型。关键是要使用引用相等而不是混淆二进制表示。将这些内容留给低级语言，确保您的代码不仅智能，而且易于阅读和维护。

使用linq通过多项选择结果创建单向表是否有好方法？

2 个答案: