<?php

/**
 * Class Matrix
 *
 * @author  Edgar Asatryan <nstdio@gmail.com>
 */
class Matrix
{
    private $data;
    private $rows;
    private $cols;

    public function __construct(array $data)
    {
        $this->data = $data;
        $this->rows = count($data);
        $this->cols = count($data[0]);
    }

    public function mul(Matrix $matrix)
    {
        $data = $matrix->getData();

        $result = [];
        for ($i = 0; $i < $this->rows; $i++) {
            for ($j = 0; $j < $this->cols; $j++) {
                $t = 0;
                for ($k = 0; $k < $this->rows; $k++) {
                    $t += $this->data[$i][$k] * $data[$k][$j];
                }
                $result[$i][$j] = $t;
            }
        }

        return $result;
    }

    /**
     * @return array
     */
    public function getData()
    {
        return $this->data;
    }

    public function add(Matrix $matrix)
    {
        $data = $matrix->getData();
        $result = [];
        for ($i = 0; $i < $this->rows; $i++) {
            for ($j = 0; $j < $this->cols; $j++) {
                $result[$i][$j] = $this->data[$i][$j] + $data[$i][$j];
            }
        }

        return $result;
    }

    public function sub(Matrix $matrix)
    {
        $data = $matrix->getData();
        $result = [];
        for ($i = 0; $i < $this->rows; $i++) {
            for ($j = 0; $j < $this->cols; $j++) {
                $result[$i][$j] = $this->data[$i][$j] - $data[$i][$j];
            }
        }

        return $result;
    }

    public function scalarMul($number)
    {
        $result = [];
        for ($i = 0; $i < $this->rows; $i++) {
            for ($j = 0; $j < $this->cols; $j++) {
                $result[$i][$j] = $this->data[$i][$j] * $number;
            }
        }

        return new Matrix($result);
    }