Task: Top rank per group




Go: package main

import (
    "fmt"
    "sort"
)


type Employee struct {
    Name, ID string
    Salary   int
    Dept     string
}

type EmployeeList []*Employee

var data = EmployeeList{
    {"Tyler Bennett", "E10297", 32000, "D101"},
    {"John Rappl", "E21437", 47000, "D050"},
    {"George Woltman", "E00127", 53500, "D101"},
    {"Adam Smith", "E63535", 18000, "D202"},
    {"Claire Buckman", "E39876", 27800, "D202"},
    {"David McClellan", "E04242", 41500, "D101"},
    {"Rich Holcomb", "E01234", 49500, "D202"},
    {"Nathan Adams", "E41298", 21900, "D050"},
    {"Richard Potter", "E43128", 15900, "D101"},
    {"David Motsinger", "E27002", 19250, "D202"},
    {"Tim Sampair", "E03033", 27000, "D101"},
    {"Kim Arlich", "E10001", 57000, "D190"},
    {"Timothy Grove", "E16398", 29900, "D190"},
    
    {"Tie A", "E16399", 29900, "D190"},
    {"Tie B", "E16400", 29900, "D190"},
    {"No Tie", "E16401", 29899, "D190"},
}









type By func(e1, e2 *Employee) bool
type employeeSorter struct {
    list EmployeeList
    by   func(e1, e2 *Employee) bool
}

func (by By) Sort(list EmployeeList)         { sort.Sort(&employeeSorter{list, by}) }
func (s *employeeSorter) Len() int           { return len(s.list) }
func (s *employeeSorter) Swap(i, j int)      { s.list[i], s.list[j] = s.list[j], s.list[i] }
func (s *employeeSorter) Less(i, j int) bool { return s.by(s.list[i], s.list[j]) }










func (el EmployeeList) TopSalariesByDept(n int) []EmployeeList {
    if n <= 0 || len(el) == 0 {
        return nil
    }
    deptSalary := func(e1, e2 *Employee) bool {
        if e1.Dept != e2.Dept {
            return e1.Dept < e2.Dept
        }
        if e1.Salary != e2.Salary {
            return e1.Salary > e2.Salary
        }
        
        return e1.ID < e2.ID
    }

    
    
    
    
    sorted := make(EmployeeList, len(el))
    copy(sorted, el)
    By(deptSalary).Sort(sorted)

    perDept := []EmployeeList{}
    var lastDept string
    var lastSalary int
    for _, e := range sorted {
        if e.Dept != lastDept || len(perDept) == 0 {
            lastDept = e.Dept
            perDept = append(perDept, EmployeeList{e})
        } else {
            i := len(perDept) - 1
            if len(perDept[i]) >= n && e.Salary != lastSalary {
                continue
            }
            perDept[i] = append(perDept[i], e)
            lastSalary = e.Salary
        }
    }
    return perDept
}

func main() {
    const n = 3
    top := data.TopSalariesByDept(n)
    if len(top) == 0 {
        fmt.Println("Nothing to show.")
        return
    }
    fmt.Printf("Top %d salaries per department\n", n)
    for _, list := range top {
        fmt.Println(list[0].Dept)
        for _, e := range list {
            fmt.Printf("    %s %16s %7d\n", e.ID, e.Name, e.Salary)
        }
    }
}








Ada: with Ada.Containers.Vectors;
with Ada.Text_IO;

procedure Top is
   type Departments is (D050, D101, D190, D202);
   type Employee_Data is record
      Name       : String (1 .. 15);
      ID         : String (1 .. 6);
      Salary     : Positive;
      Department : Departments;
   end record;

   package Employee_Vectors is new Ada.Containers.Vectors
     (Element_Type => Employee_Data, Index_Type => Positive);

   function Compare_Salary (Left, Right : Employee_Data) return Boolean is
   begin
      return Left.Salary > Right.Salary;
   end Compare_Salary;
   package Salary_Sort is new Employee_Vectors.Generic_Sorting
     ("<" => Compare_Salary);

   function Compare_Department (Left, Right : Employee_Data) return Boolean is
   begin
      return Left.Department < Right.Department;
   end Compare_Department;
   package Department_Sort is new Employee_Vectors.Generic_Sorting
     ("<" => Compare_Department);

   Example_Data : Employee_Vectors.Vector;
begin
   
   Example_Data.Append (("Tyler Bennett  ", "E10297", 32000, D101));
   Example_Data.Append (("John Rappl     ", "E21437", 47000, D050));
   Example_Data.Append (("George Woltman ", "E00127", 53500, D101));
   Example_Data.Append (("Adam Smith     ", "E63535", 18000, D202));
   Example_Data.Append (("Claire Buckman ", "E39876", 27800, D202));
   Example_Data.Append (("David McClellan", "E04242", 41500, D101));
   Example_Data.Append (("Rich Holcomb   ", "E01234", 49500, D202));
   Example_Data.Append (("Nathan Adams   ", "E41298", 21900, D050));
   Example_Data.Append (("Richard Potter ", "E43128", 15900, D101));
   Example_Data.Append (("David Motsinger", "E27002", 19250, D202));
   Example_Data.Append (("Tim Sampair    ", "E03033", 27000, D101));
   Example_Data.Append (("Kim Arlich     ", "E10001", 57000, D190));
   Example_Data.Append (("Timothy Grove  ", "E16398", 29900, D190));
   
   Salary_Sort.Sort (Example_Data);
   
   for Department in Departments loop
      declare
         Position : Employee_Vectors.Cursor := Example_Data.First;
         Employee : Employee_Data;
      begin
         Ada.Text_IO.Put_Line ("Department " & Departments'Image (Department));
         for I in 1 .. 3 loop
            Employee := Employee_Vectors.Element (Position);
            while Employee.Department /= Department loop
               Position := Employee_Vectors.Next (Position);
               Employee := Employee_Vectors.Element (Position);
            end loop;
            Ada.Text_IO.Put_Line ("   " & Employee.Name & " | " &
                                  Employee.ID & " | " &
                                  Positive'Image (Employee.Salary));
            Position := Employee_Vectors.Next (Position);
         end loop;
      exception
         when Constraint_Error =>
            null;
      end;
   end loop;
end Top;