int numBalls = 25;
float spring = 0.05;

float friction = -0.9;
Ball[] balls = new Ball[numBalls];

void setup() 
{
  size(400, 400);
  noStroke();
  smooth();
  for (int i = 0; i < numBalls; i++) {
    balls[i] = new Ball(random(width), random(height), random(20, 40), i, balls);
  }
}

void draw() 
{
  background(255);
  for (int i = 0; i < numBalls; i++) {
    balls[0].x=mouseX;
    balls[0].y=mouseY;
    
    balls[i].collide();
    balls[i].move();
    balls[i].display();  
  }
}