Method add

ProductOfTheLastKNumbers.java:7–14

(int num)

    }
    
    public void add(int num) {
        if(num==0){
            list.clear();
            return;
        }
        int prev = (list.size()==0)?1:list.get(list.size()-1);
        list.add(prev * num);
    }
    
    public int getProduct(int k) {
        int s = list.size();