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)
        }
    }
}

PHP: $data = Array(
            Array("Tyler Bennett","E10297",32000,"D101"),
            Array("John Rappl","E21437",47000,"D050"),
            Array("George Woltman","E00127",53500,"D101"),
            Array("Adam Smith","E63535",18000,"D202"),
            Array("Claire Buckman","E39876",27800,"D202"),
            Array("David McClellan","E04242",41500,"D101"),
            Array("Rich Holcomb","E01234",49500,"D202"),
            Array("Nathan Adams","E41298",21900,"D050"),
            Array("Richard Potter","E43128",15900,"D101"),
            Array("David Motsinger","E27002",19250,"D202"),
            Array("Tim Sampair","E03033",27000,"D101"),
            Array("Kim Arlich","E10001",57000,"D190"),
            Array("Timothy Grove","E16398",29900,"D190")
            );
function top_sal($num){
    global $data;
    $depts = Array();
    foreach($data as $key => $arr){
        if(!isset($depts[$arr[3]])) $depts[$arr[3]] = Array();
        $depts[$arr[3]][] = $key;
    }   
    function topsalsort($a,$b){
        global $data;
        if ($data[$a][2] == $data[$b][2]) {
            return 0;
        }
        return ($data[$a][2] < $data[$b][2]) ? 1 : -1;
    }
    foreach ($depts as $key => $val){
        usort($depts[$key],"topsalsort");
    }
    ksort($depts);
    echo '<pre>';
    foreach ($depts as $key => $val){
        echo $key . '<br>';
        echo 'Name          ID      Salary<br>';
        $count = 0;
        foreach($val as $value){
            echo $data[$value][0] . '   ' . $data[$value][1] . '    ' . $data[$value][2] . '<br>';
            $count++;
            if($count>=$num) break;
        }
        echo '<br>';
    }
    echo '</pre>';
}
top_sal(3);