Algorithm-face test more than 20,000 employees by age sorting algorithm

More than 20,000 employees by age ranking algorithm,

Algorithm thinking is the idea of choosing a sort algorithm, taking into account more than 20,000 employees, at a certain age when the value of a number of employees will have the actual situation.

Ideas
The first search to find, the minimum age of M minage, the maximum age of N MaxAge, so that the age of the range [Minage, MaxAge]; second, search step 1, all found, after the M minage, in turn ...

C # code implementation,

Personnel model for,

public class person
{public person
   (int staffno, int age)
   {
     this.staffno = staffno;
     This.age = age;
   }
   Work number public
   int staffno {get;set;}
   Age public
   int age{get;set;}
  }

Step to 1 sorting search algorithm:

        static void sort ()
        {
            if (list = = null) return;
            Find out who is the youngest of the list
            list<person> minagepersons = getagepersons (list. Min (per => per.age));

            Find out who is the oldest list
            list<person> maxagepersons = getagepersons (list. Max (per => per.age));

           Remove these values
            list = list. Except (minagepersons). Except (maxagepersons). ToList ();

            for (int age = minagepersons[0].age+1;age<maxagepersons[0].age;age++)
            {
                list<person> agepersons = Getagepersons (age);
                Minagepersons.addrange (agepersons);
                List. Except (agepersons);
            }

            Minagepersons.addrange (maxagepersons);
            list = minagepersons;
        }

        static list<person> getagepersons (int age)
        {return
            List. FindAll (person => person.age = = age);
        }

The age of the person does not necessarily step into 1, so improve the sort (),

        static void sort ()
        {
            if (list = = null) return;
            Find out who is the youngest of the list
            list<person> minagepersons = getagepersons (list. Min (per => per.age));
            List = list. Except (minagepersons). ToList ();
            Do
            {                
                list<person> tmpminagepersons = getagepersons (List. Min (per => per.age));
                Minagepersons.addrange (tmpminagepersons);
                List = list. Except (tmpminagepersons). ToList ();
            } while (list. Count > 0);

            list = minagepersons;
        }

Source Address:
After downloading, list = list. Except (minagepersons). ToList () moves outside the Do loop. (a small problem that was found after uploading the code)
http://download.csdn.net/detail/daigualu/9782742