Reduce loops into one - TIPS ONLY [closed]

Question

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Closed 9 years ago.

Rewrite the code below so it would contain only one loop and only one itterational variable would be used.

$result = Array();
for ($x = 0; $x < 6; $x++){
    for ($y = 0; $y < 6; $y++){
        for ($z = 0; $z < 6; $z++){
            $result[$x][$y][$z] = $x * $y * $z;
        }
    }
}

NO ANSWERS PLEASE, JUST POINT ME IN THE RIGHT DIRECTION. Is there a php class that can handle this? Or is it just a simple problem solving technique? Or is it a trick question?

Recommended result below:

$result = Array();
for ($i = 0; $i < 216; $i++){
    $x = $i % 6;
    $y = floor($i/6) % 6;
    $z = floor($i/36);
    $result[$x][$y][$z] = $x * $y * $z;
}

Answer 1

Missing the homework flag?

Think in base 6, and run a loop from zero to 6^3 (216) then use mod to reduce/shift back into x y z positions.

Answer 2

Pro Tip #1: You can have multiple variable operations in a single for loop...

for($a = 0, $b = 10; $b > $a; $b++, $a--) {
    echo $a . $b;
}