rotate Array Linear Algebra

rotateArrayLinearAlgebra.php

<?php

function matMul($a,$b){
    $countI = count($a);
    $countJ = count($b[0]);
    $countK = count($b);
    $c=[];
    for($i=0;$i<$countI;$i++){
        for($j=0;$j<$countJ;$j++){
            $sum = 0;
            for($k=0;$k<$countK;$k++){
                $sum += $a[$i][$k] * $b[$k][$j];
            }
            $c[$i][$j] = $sum;
        }
    }
    return $c;
}

function rotateArrayLeft($a){
    $aR = count($a);
    $aC = count($a[0]);
    $rotMatrix = [[0,-1]
                 ,[1,0]];
    $rotated = [];
    for($i=0;$i<$aR;$i++){
        for($j=0;$j<$aC;$j++){
            $newCoords = matMul($rotMatrix,[[$i],[$j]]);
            $rotated[$newCoords[0][0]+$aR][$newCoords[1][0]] = $a[$i][$j];
        }
    }
    //$rotated =
    //$rotated = array_values($rotated);
    ksort($rotated);
    print_r($rotated);
}

rotateArrayLeft([[1,2,3],[4,5,6]]);