<?php
interface Rownanie
{
    public function wyswietl(Dane $dane);
    public function setDane(Dane $dane);
}

class Dane implements Rownanie
{
    private $in;

    public function __construct(){
        $this->tab[] = 0;
        $this->tab[] = 1;
        $this->tab[] = 2;
        $this->tab[] = 3;
    }

    public function getA(){return $this->tab[0];}
    public function getB(){return $this->tab[1];}
    public function getC(){return $this->tab[2];}
    public function getD(){return $this->tab[3];}

    public function setDane(Dane $dane){
        $dane->tab[0] = -2;
        $dane->tab[1] = -3;
        $dane->tab[2] = -4;
        $dane->tab[3] = -5;
    }

    public function wyswietl(Dane $dane){
        if($dane->getA()!=0)echo $dane->getA(),"xx ";

        if(($dane->getA() == 0 && $dane->getB()!=0) || ($dane->getB()!=0 && $dane->getB()<0))echo $dane->getB(),"x ";
        else if($dane->getB()!=0) echo " + " , $dane->getB() ,  "x";

        if($dane->getC()!=0 && $dane->getC()<0)echo " " , $dane->getC()," ";
        else if($dane->getC()!=0) echo " + ",$dane->getC();

        if($dane->getD() != 0 && $dane->getD()<0)echo $dane->getD() ,"i";
        if($dane->getD() != 0 && $dane->getD()>0)echo " + " , $dane->getD() ,"i";
        echo "<br>";
    }
}

class Delta extends Dane implements Rownanie
{
    protected $deltar;
    protected $deltau;
    protected $cz_rz;
    protected $cz_ur;

    public function __construct()
    {
        $deltar = 0.0;
        $deltau = 0.0;
        $cz_rz = 0.0;
        $cz_ur = 0.0;
    }
    public function getCzRz(){return $this->cz_rz;}
    public function getCzUR(){return $this->cz_ur;}

    public function setDane(Dane $dane)
    {
        $this->deltar = $dane->getB()* $dane->getB() - 4 * $dane->getA() * $dane->getC();
        $this->deltau = -4 *$dane->getA()* $dane->getD();

        $this->cz_rz = sqrt((sqrt(($this->deltar * $this->deltar) + ($this->deltau * $this->deltau)) + $this->deltar)/2);
        $this->cz_ur = sqrt((sqrt(($this->deltar * $this->deltar) + ($this->deltau * $this->deltau)) - $this->deltar)/2);
    }
    public function wyswietl(Dane $dane)
    {
        if($dane->getA()!=0 && $dane->getD() ==0)
        {
            echo "Delta = ",$this->deltar, "<br>";
        }
        if($dane->getA() != 0 && $dane->getD() != 0)
        {
            if($this->deltau>0)echo "DELTA = ",$this->deltar," + ",$this->deltau ,"i <br>";
            if($this->deltau<0)echo "DELTA = ",$this->deltar," ",$this->deltau ,"i <br>";
        }
    }

}

class ObliczRownanie extends Delta implements Rownanie
{
    protected $x1r,$x2r,$x3r,$x4r;
    protected $x1u,$x2u,$x3u,$x4u;

    public function __construct(){
        $this->x1r = 0.0; $this->x2r = 0.0; $this->x3r = 0.0; $this->x4r = 0.0;
        $this->x1u = 0.0; $this->x2u = 0.0; $this->x3u = 0.0; $this->x4u = 0.0;
    }

    public function setDane(Dane $dane)
    {
        echo "ASD";
    }
    public function wyswietl(Dane $dane)
    {
        echo "ASD";
    }

}
?>