随机从规则库中去取尽规则

Posted 2022-01-26 滴滴哒滴哒

        新接了一个需求，大致要求每日定量从规则库中去规则，一天的规则不重复，并在一定天数取完。考虑到取完和不重复的特性，决定用栈去实现。

public class RandomListTest<E> 

    public void getRandomValue(List<E> list,Integer numsPerDay,Integer days)
        //初始化
        LinkedList<E> stack1 = new LinkedList<>();
        LinkedList<E> stack2 = new LinkedList<>();
        for (int i = 0; i < list.size(); i++) 
            stack1.push(list.get(i));
        
        //随机
        Collections.shuffle(stack1);

        for (int i = 0; i < days; i++) 
            if (stack1.size() >= numsPerDay)
                for (int j = 0; j < numsPerDay; j++) 
                    //TODO stack1.peek()
                    System.out.println(stack1.peek());
                    stack2.push(stack1.pop());
                
            else 
                int dist = numsPerDay - stack1.size();
                for (int j = 0; j < stack1.size(); j++) 
                    //TODO stack1.get(j)
                    System.out.println(stack1.get(j));
                
                //随机
                Collections.shuffle(stack2);
                for (int j = 0; j < dist; j++) 
                    //TODO stack2.peek()
                    System.out.println(stack2.peek());
                    stack1.push(stack2.pop());
                
                //互换
                LinkedList<E> temp = stack1;
                stack1 = stack2;
                stack2 = temp;