<?php


    $products = $_GET['list'];
    $productsArray = explode(", ", $products);
    $CPUCount = 0;
    $RAMCount = 0;
    $VIACount = 0;
    $ROMCount = 0;
    foreach ($productsArray as $product){
        switch($product){
            case 'CPU': $CPUCount++;
                break;
            case 'RAM': $RAMCount++;
                break;
            case 'ROM': $ROMCount++;
                break;
            case 'VIA': $VIACount++;
                break;
            default: //do nothing;
                break;
        }
    }
    $CPUPrice = 85;
    $RAMPrice = 35;
    $ROMPrice = 45;
    $VIAPrice = 45;
    if ($CPUCount >=5 ){
        $CPUPrice /= 2;
    }
    if ($RAMCount >=5 ) {
        $RAMPrice /= 2;
    }
    if ($ROMCount >= 5) {
        $ROMPrice /= 2;
    }
    if ($VIACount >= 5) {
        $VIAPrice /= 2;
    }
    $expenses = $CPUCount*$CPUPrice + $RAMCount*$RAMPrice +
        $ROMCount*$ROMPrice + $VIACount*$VIAPrice;
    //this is how many computers could be assembled:
    $assembledComputers = min($CPUCount, $RAMCount,
        $ROMCount, $VIACount);
    //....
    $profitFromSoldPCs = $assembledComputers * 420;
    //this is how many parts we have left:
    $CPUCount -= $assembledComputers;
    $RAMCount -= $assembledComputers;
    $VIACount -= $assembledComputers;
    $ROMCount -= $assembledComputers;
    $partsLeft = $CPUCount + $RAMCount + $VIACount + $ROMCount;
    //....
    $profitFromPartsLeft = $CPUCount*85/2 + $RAMCount*35/2 +
        $ROMCount*45/2 + $VIACount*45/2;
    $profit = $profitFromSoldPCs + $profitFromPartsLeft;
    $balance = $profit - $expenses;
    echo "<ul><li>".$assembledComputers." computers assembled</li><li>".
        $partsLeft." parts left</li></ul>";
    if ($balance > 0){
        echo "<p>Nakov gained ". $balance. " leva</p>";
    } else {
        echo "<p>Nakov lost " .$balance. " leva</p>";
    }

?>