如何通过Linq分区然后按不同属性分组

Question

Suppose a class like this below

public class Student
{
    public string Name {get;set;}
    public string Topic {get;set;}
    public string Age {get;set;}
}

and a list like this

var students = new List<Student>();

with data:

Name           Topic       Age
S1             alpha       15
S2             beta        15
S3             gamma       17
S4             theta       16
S5             alpha       15
S6             alpha       17
S7             gamma       17
S8             theta       18
S9             alpha       19

..

I need to create a dataset like below out of the students list

Topic  15    16    17   18   19
alpha  2      0    1    0     1
beta   1      0    0    0     0
gamma  0      0    2    0     0
theta  0      1    0    1     0 

what is the best way to go about solving this without having to create a strongly typed dataset with properties 15,16..

Is there a way I can partition my collection using linq to generate an anonymous datastructure like just above?

Also, was not sure on how to word the question, hence if you think title of the question is totally misleading, please suggest how can I improve the title

Answer 1

    Dictionary<string,IGrouping<int,Student>> partition = students.GroupBy(s=> s.Topic).
     ToDictionary(grp=> grp.Key, grp=> grp.GroupBy(g=> g.Age));

This will give you a dictionary of all Topics to a grouping by age a simple count on the grouping will give you the amount. This is off the cuff without intellisense so you might need to fix a bad naming or 2