[ace12364]

Do you understand this? I have added some comments of my own iunderstanding, but i would be grateful someone could justify it?

public int levelbottom(int v)
     //0->0, 1->6, 2->11, 3->15, 4->18, 5->20, 6->21
        {return (21 - ((6-v)*(7-v))/2);
        }        
     
     
             
     public boolean better(int a, int b, int c)
 //Is c closer to a than b is to a?
        {return (((b<c) && (b-a<a-c)) || ((c<b) && (a-c<b-a)));
        }
           
     public int calc(int h, int l, int f) 
     //doing the calculation?   
        {switch (f)
            {case 0:  return h+l; // addition
             case 1:  return h-l; // subtraction
             case 2:  return h*l; // multiplication
             case 3:  return h/l; // division
             default: 
            }
         return 0; // should not arrive here?