<?php
error_reporting(15);
function a1()
{
    $ages = array(48,24,23,12,45,56,67,33,35,42,12,14,15,27);
    $i = 0;
    echo "<pre>";
    echo "//GOsha:".PHP_EOL;
    $s1 = microtime();
    $groups = array(range(0,18),range(19,30),range(31,50),range(51,100));
    $result = array(0=>0,1=>0,2=>0,3=>0);
    foreach($ages as $age)
    {
        foreach($groups as $k=>$group)
        {
            $i++;
            if(in_array($age,$group)){
                @$result[$k]++;
                break;
            }
        }
    }
    print_r($result);

    $s2 = microtime();
    $e = $s2-$s1;
    echo "time:".$e.PHP_EOL;
    echo "iterations:".$i.PHP_EOL;
    echo "</pre>";
}

function a2()
{

    $ages = array(48,24,23,12,45,56,67,33,35,42,12,14,15,27);
    $i=0;
    echo "<pre>";
    echo "//vitaliyp:".PHP_EOL;
    $s1 = microtime();
    $groupped = array('0-18'=>0,'18-30'=>0,'30-50'=>0,'50-100'=>0);
    foreach($ages as $a){
      switch($a){
        case in_array($a,range(0,18)):
          $groupped['0-18']++;
          break;
        case in_array($a,range(18,30)):
          $groupped['18-30']++;
          break;
        case in_array($a,range(30,50)):
          $groupped['30-50']++;
          break;
        case in_array($a,range(50,100)):
          $groupped['50-100']++;
          break;
      }
      $i++;
    }

    print_r($groupped);
    $s2 = microtime();
    $e = $s2-$s1;
    echo "time:".$e.PHP_EOL;
    echo "iterations:".$i.PHP_EOL;
    echo "</pre>";
}

function a3()
{
    $ages = array(48,24,23,12,45,56,67,33,35,42,12,14,15,27);
    $i = 0;
    echo "<pre>";
    echo "//sectus:".PHP_EOL;
    $s1 = microtime();
    $all_ages = array_count_values($ages) + array_fill(0, 101, 0);
    ksort($all_ages);
    $groupped['0-18'] = array_sum(array_slice($all_ages, 0, 19));
    $groupped['19-30']= array_sum(array_slice($all_ages, 19, 12));
    $groupped['31-50']= array_sum(array_slice($all_ages, 31, 20));
    $groupped['51-100']= array_sum(array_slice($all_ages, 51, 50));
    print_r($groupped);
    $s2 = microtime();
    $e = $s2-$s1;
    echo "time:".$e.PHP_EOL;
    echo "iterations:".$i.PHP_EOL;
    echo "</pre>";
}

function a4()
{
    $result = array('18'=>0,'30'=>0,'50'=>0,'100'=>0);
    $ages = array(48,24,23,12,45,56,67,33,35,42,12,14,15,27);
    $i = 0;
    echo "<pre>";
    echo "//evts85:".PHP_EOL;
    $s1 = microtime();
    foreach($ages as $age){
        foreach($result as $key => $value){
            $i++;
            if($age < $key){
                $result[$key]++;
                break;
            }
         }
    }
    print_r($result);
    $s2 = microtime();
    $e = $s2-$s1;
    echo "time:".$e.PHP_EOL;
    echo "iterations:".$i.PHP_EOL;
    echo "</pre>";
}

function a5()
{
    $ages = array(48,24,23,12,45,56,67,33,35,42,12,14,15,27);
    $i = 0;
    echo "<pre>";
    echo "//tempman:".PHP_EOL;
    $s1 = microtime();
    rsort($ages);
    $rages = array('18'=>0,'30'=>0,'50'=>0,'100'=>0);
    $ages_count = count($ages);
    $prev_pos = 0;
    $prev_limit = 0;
    foreach ($rages as $k => $v){

      $index = $k; //
      do{
        $i++;
        $pos = array_search($index,$ages);
        if($pos!==false)
        {

        $prev_pos += $rages[$k]= $ages_count - $pos - $prev_pos;
        };
        $index--;

      }while($pos===false  && ($index > $prev_limit));
      $prev_limit = $v;
    }
    print_r($rages);
    $s2 = microtime();
    $e = $s2-$s1;
    echo "time:".$e.PHP_EOL;
    echo "iterations:".$i.PHP_EOL;
    echo "</pre>";
}

function a6()
{
    $ages = array(48,24,23,12,45,56,67,33,35,42,12,14,15,27);
    $i = 0;
    echo "<pre>";
    echo "//if..else:".PHP_EOL;
    $s1 = microtime();
    $result = array(0=>0,1=>0,2=>0,3=>0);
    foreach($ages as $age)
    {
        $i++;
        if($age <=18) $result[0]++;
        if($age >18 && $age<=30) $result[1]++;
        if($age >30 && $age<=50) $result[2]++;
        if($age >50 && $age<=100) $result[3]++;
    }
    print_r($result);

    $s2 = microtime();
    $e = $s2-$s1;
    echo "time:".$e.PHP_EOL;
    echo "iterations:".$i.PHP_EOL;
    echo "</pre>";
}

a1();
a2();
a3();
a4();
a5();
a6();
?>