当前位置：首页 > news >正文

集合练习1

news 2025/11/16 14:07:53

练习一

班级里有N个学生,实现随机点名器

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;public class 练习1 {public static void main(String[] args) {List<String> list = new ArrayList<String>();
//        方法一:Collections.addAll(list,"张伟", "王芳", "李娜", "刘洋", "陈静","杨帆", "黄磊", "赵薇", "周杰", "吴刚","孙丽", "朱强", "徐敏", "马超", "胡军","林峰", "郭靖", "何洁", "高伟", "梁静","郑凯", "谢娜", "宋佳", "唐嫣", "董洁","袁泉", "邓超", "韩梅", "蔡徐", "彭于");Random random = new Random();int index = random.nextInt(list.size());System.out.println(list.get(index));
//        方法二:Collections.shuffle(list);System.out.println(list.get(0));}
}

练习二

班级里有N个学生,实现随机点名器

要求:

被点到的学生不会再被点到
如果所有学生都被点完了,需要重新开启第二轮点名

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;public class 练习2 {public static void main(String[] args) {List<String> boyList = new ArrayList<>();List<String> girlList = new ArrayList<>();List<Integer> list = new ArrayList<>();Collections.addAll(boyList, "张伟", "刘洋", "杨帆","黄磊", "周杰", "吴刚", "朱强","马超", "胡军", "林峰", "郭靖","高伟", "郑凯", "袁泉", "邓超","蔡徐", "彭于");Collections.addAll(girlList, "王芳", "李娜", "陈静","赵薇", "孙丽", "徐敏", "何洁","梁静", "谢娜", "宋佳", "唐嫣","董洁", "韩梅");Collections.addAll(list,1,1,1,1,1,1,1,0,0,0);Random random = new Random();int index = random.nextInt(list.size());int number = list.get(index);if(number ==1){int boyIndex = random.nextInt(boyList.size());System.out.println(boyList.get(boyIndex));}else if (number ==0){int girlIndex = random.nextInt(girlList.size());System.out.println(girlList.get(girlIndex));}}
}

练习三:

班级里有N个学生,实现随机点名器

要求:

被点到的学生不会再被点到
如果所有学生都被点完了,需要重新开启第二轮点名
70%随机到男生,30%随机到女生

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;public class 练习3 {public static void main(String[] args) {List<String> list1 = new ArrayList<>();List<String> list2 = new ArrayList<>();Collections.addAll(list1, "张伟", "王芳", "李娜", "刘洋", "陈静","杨帆", "黄磊", "赵薇", "周杰", "吴刚","孙丽", "朱强", "徐敏", "马超", "胡军","林峰", "郭靖", "何洁", "高伟", "梁静","郑凯", "谢娜", "宋佳", "唐嫣", "董洁","袁泉", "邓超", "韩梅", "蔡徐", "彭于");int count = list1.size();Random random = new Random();for (int l = 0; l < count; l++) {System.out.println("=========第"+l+"轮开始============");for (int i = 0; i < count; i++) {int index = random.nextInt(list1.size());String name = list1.remove(index);list2.add(name);System.out.println(name);}list1.addAll(list2);list2.clear();}}
}