bool Map::blocked(float x, float y)
{
    //x= columns
    //y =lines
    return array[(int) y][(int) x]!=0;
}

monsters::monsters():speed(5){

    startX=0;
    startY=0;

    qsrand(time(NULL));
  //Set a random start position in the map-> the array is [12][8]
    do{
        startX= qrand() % 12;
        startY= qrand() % 8;

    }while(!map->blocked(startX, startY));


    int arrayDirection [2]= {-50, 50};//first move= 1 direction among two -> left of right?
    int x= qrand() %2;
    direction= arrayDirection[x];



}

QRectF monsters::boundingRect() const{
    return QRectF(0,0, size_element, size_element);
}

void monsters::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget){
    painter->drawPixmap(0,0,size_element,size_element,QPixmap("path to the image"));
}

void monsters::moveOnMap(){

    QTimer *t = new QTimer(this);
    connect(t,SIGNAL(timeout()),this,SLOT(advance()));
    t->start(50);

}

void monsters::advance(){

    //my tile size is 50x50 so I have to divide by 50  my direction to get my array index

    switch(direction){

    case 50:

        if(!map->blocked((direction/50), startY)){
            moveBy(direction,startY);
        }
        else
        {
            moveBy(-(direction)/,startY);//move in the opposite directions
        }

        direction+=50;

    case -50:

        if(!map->blocked((direction/50), startY)){
            moveBy(direction,startY);
        }
        else
        {
            moveBy(-(direction),startY);
        }
    }

}

int nbMonsters=5;

for(int i=0; i<nbMonsters; i++){
    monsters *monster= new monsters();
    monster->setPos(monster->getPostionX(), monster->getPostionY());
    myMap->getScene()->addItem(monster);

}

getPositionX and getPositionY