Set_advanced_project/Set_case_module/src/Case_demo2/Test2.java

package Case_demo2;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Random;

public class Test2 {
    public static void main(String[] args) {
        /*
        班级里有N个学生
        要求：
            70%的概率随机到男生
            30%的概率随机到女生

         "范闲", "范建", "范统", "杜子腾", "朱合泛", "侯笼藤", "朱益群", "朱穆朗玛峰"
         "杜琦燕", "袁明媛", "李猜", "田密密"
         */

        //1、创建集合
        ArrayList<Integer> list = new ArrayList<>();
        //2、添加数据
        Collections.addAll(list, 1, 1, 1, 1, 1, 1, 1);
        Collections.addAll(list, 0, 0, 0);
        //3、打乱集合中的数据
        Collections.shuffle(list);

        //4、从list集合中随机抽取0或者1
        Random r = new Random();
        int index = r.nextInt(list.size());
        int number = list.get(index);
        System.out.println(number);

        //5、创建两个集合分别存储男生和女生的名字
        ArrayList<String> boyList = new ArrayList<>();
        ArrayList<String> girlList = new ArrayList<>();

        Collections.addAll(boyList, "范闲", "范建",
                "范统", "杜子腾", "朱合泛", "侯笼藤", "朱益群", "朱穆朗玛峰");
        Collections.addAll(girlList, "杜琦燕", "袁明媛", "李猜", "田密密");

        //6、判断此时是从boyList里面抽取还是从girlList里面抽取
        if (number == 1) {
            //boyList
            int boyIndex = r.nextInt(boyList.size());
            String name = boyList.get(boyIndex);
            System.out.println(name);
        } else {
            //girlList
            int girlIndex = r.nextInt(girlList.size());
            String name = girlList.get(girlIndex);
            System.out.println(name);
        }
    }
}