Task: Top rank per group
C++: #include <string>
#include <set>
#include <list>
#include <map>
#include <iostream>


struct Employee
{
    std::string Name;
    std::string ID;
    unsigned long Salary;
    std::string Department;
    Employee(std::string _Name = "", std::string _ID = "", unsigned long _Salary = 0, std::string _Department = "")
    : Name(_Name), ID(_ID), Salary(_Salary), Department(_Department)
    { }

    void display(std::ostream& out) const
    {
        out << Name << "\t" << ID << "\t" << Salary << "\t" << Department << std::endl;
    }
};


struct CompareEarners
{
    bool operator()(const Employee& e1, const Employee& e2)
    {
        return (e1.Salary > e2.Salary);
    }
};


typedef std::list<Employee> EMPLOYEELIST;



typedef std::set<Employee, CompareEarners> DEPARTMENTPAYROLL;

typedef std::map<std::string, DEPARTMENTPAYROLL> DEPARTMENTLIST;

void initialize(EMPLOYEELIST& Employees)
{
    
    Employees.push_back(Employee("Tyler Bennett", "E10297", 32000, "D101"));
    Employees.push_back(Employee("John Rappl", "E21437", 47000, "D050"));
    Employees.push_back(Employee("George Woltman", "E21437", 53500, "D101"));
    Employees.push_back(Employee("Adam Smith", "E21437", 18000, "D202"));
    Employees.push_back(Employee("Claire Buckman", "E39876", 27800, "D202"));
    Employees.push_back(Employee("David McClellan", "E04242", 41500, "D101"));
    Employees.push_back(Employee("Rich Holcomb", "E01234", 49500, "D202"));
    Employees.push_back(Employee("Nathan Adams", "E41298", 21900, "D050"));
    Employees.push_back(Employee("Richard Potter", "E43128", 15900, "D101"));
    Employees.push_back(Employee("David Motsinger", "E27002", 19250, "D202"));
    Employees.push_back(Employee("Tim Sampair", "E03033", 27000, "D101"));
    Employees.push_back(Employee("Kim Arlich", "E10001", 57000, "D190"));
    Employees.push_back(Employee("Timothy Grove", "E16398", 29900, "D190"));
}

void group(EMPLOYEELIST& Employees, DEPARTMENTLIST& Departments)
{
    
    for( EMPLOYEELIST::iterator iEmployee = Employees.begin();
         Employees.end() != iEmployee;
         ++iEmployee )
    {
        DEPARTMENTPAYROLL& groupSet = Departments[iEmployee->Department];

        
        groupSet.insert(*iEmployee);
    }
}

void present(DEPARTMENTLIST& Departments, unsigned int N)
{
    
    for( DEPARTMENTLIST::iterator iDepartment = Departments.begin();
         Departments.end() != iDepartment;
         ++iDepartment )
    {
        std::cout << "In department " << iDepartment->first << std::endl;
        std::cout << "Name\t\tID\tSalary\tDepartment" << std::endl;
        
        unsigned int rank = 1;
        for( DEPARTMENTPAYROLL::iterator iEmployee = iDepartment->second.begin();
             ( iDepartment->second.end() != iEmployee) && (rank <= N);
             ++iEmployee, ++rank )
        {
            iEmployee->display(std::cout);
        }
        std::cout << std::endl;
    }
}

int main(int argc, char* argv[])
{
    
    EMPLOYEELIST Employees;

    
    initialize(Employees);

    
    DEPARTMENTLIST Departments;

    
    
    group(Employees, Departments);

    
    present(Departments, 3);

    return 0;
}

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);