JAVA练习

A B C D四个景区，80人选择，可多选，结果统计

public class statistics {
    public static void main(String[] args) {
        Character[] str ={'A','B','C','D'};
        List list=new ArrayList<>();
        Random r =new Random();

        int randInt=0;
        for (int i = 0; i < 80; i++) {
            StringBuilder sec = new StringBuilder();

            int num=r.nextInt(str.length)+1;
                //生成不重复随机数bool[] + do while
            boolean[] bool = new boolean[str.length];

            for (int j = 0; j < num; j++) {

                do{
                    randInt = r.nextInt(str.length);
                }while(bool[randInt]);

                bool[randInt] = true;
                sec.append(str[randInt]);
            }
            list.add(sec.toString());
        }
        System.out.println(list);
        Map maps =new LinkedHashMap<>();

        for (int i = 0; i < list.size(); i++) {
            String s=list.get(i);
            for (int j = 0; j < s.length(); j++) {
                char ch=s.charAt(j);
                if (maps.containsKey(ch)){
                    maps.put(ch,maps.get(ch)+1);
                }else {
                    maps.put(ch,1);
                }

            }
            }

        System.out.println(maps);

    }
}