import java.util.Scanner;
import java.util.Vector;
//包装类测试
public class VectorTest {
public static void main(String[] args) {
int max=0;
Scanner scan=new Scanner(System.in);
Vector v=new Vector();
for (;;){
System.out.println("请输入数据:");
int score=scan.nextInt();
if(score<0){
break;
}
if (score>100){
System.out.println("非法数据!");
continue;
}
v.addElement(score);
if (max<score){
max=score;
}
}
String level;
for (int i=0;i<v.size();i++){
Object obj=v.elementAt(i);
int score=(int)obj;
if (max-score<=10){
level="A";
}else if (max-score<=20){
level="B";
}else if (max-score<=30){
level="C";
}else {
level="D";
}
System.out.println("学生"+i+"成绩是:"+score+"等级为:"+level);
}
}
}