Question

用java写一段随机抽取3个人的代码

import java.util.*;

public class CollectionExample
{
private List<String> students;
private Set<String> threeStudents;
private Map<String,Integer> choosedStudentCount;

public CollectionExample()
{
students = new ArrayList<String>();
threeStudents = new HashSet<String>();
choosedStudentCount = new HashMap<String,Integer>();
}

public static void main(String[] args)
{
CollectionExample instance = new CollectionExample();
instance.run();
}

public void run()
{
insertData();
for(int i=0;i<10;i++)
{
threeStudents.clear();
chooseThree();
//接下来输出这threeStudents
System.out.println("第" + (i+1) + "次抽到是3个人是：" + threeStudents);
}

//接下来输出choosedStudentCount的每个学生的名字及其被选到的次数
System.out.println("抽到的学生和次数为：" + choosedStudentCount);
}

public void insertData()
{
students.add("zhang3");
students.add("li4");
students.add("wang5");
students.add("ma6");
students.add("xu7");
students.add("mao18");
}

public void chooseThree()
{
}

}

Answer 1

用java.util.Radom类中的方法.
Random rd=new Random();
int persion_id=rd.nextInt(10);//这样可以得到0-10之间的一个随机数(假如总共有十个学生.)
然后用,threeStudent.add(students[stu_id])实现.
有了这个以后,就好说了.循环取得三个学生.送到threeStudent中去.
public void chooseThree()
{
Random rd=new Random();
for(int i=0;i<3;i++)
{
threeStudent.add(students[stu_id]);

}
}

祝你好运...