Question

java小题目

麻烦编写出java程序

要求:学生有若干门学科 每门学科有若干次考试

将考试总分评估等第

学科评估标准如下:
低于50 NN
50 - 59 PA
60 - 69 CR
70 - 79 DI
80 - 100 HD

执行的时候会先
要求输入有几门学科
然后输入学科1的考试次数
然后依次输入各次考试的分数
相加学科1几次考试的总分
最后总分评估出等级

在输入学科2的考试次数
然后依次输入各次考试的分数
相加学科2几次考试的总分
最后总分评估出等级

最后算出考试1的总分和考试2的总分的平均分

执行入要这样显示
Welcome to the student course admin
How many subjects are there?: 2

Collecting information for subject 0
How many assessments are there for this subject?: 2
Please enter assessment mark: 5
Please enter assessment mark: 60
Subject Mark: 65 - CR

Collecting information for subject 1
How many assessments are there for this subject?: 3
Please enter assessment mark: 10
Please enter assessment mark: 25
Please enter assessment mark: 40
Subject Mark: 75 - DI

Student Average Mark is 70

文件名为course.java
最好使用到evaluate(),getValidNum(),printMarkGrade()
调用函数evaluateSubject()

50分送上~
完成后追加50

Answer 1

import java.io.PrintStream;
import java.util.Scanner;

//学生成绩评估系统
public class CourseApplication {
private PrintStream out = System.out;
private Scanner reader = new Scanner(System.in);
private CourseEvaluation evaluation;//学生成绩评估类
/**
* 启动运行成绩评估系统
*/
public void play() {
try {
out.println("Welcome to the student course admin !");
int count = readEvaluationCount();
evaluation = new CourseEvaluation();
evaluation.assignCourseCount(count);
evaluate();
} catch (Exception ex) {
out.println("Course Application will exit!");
ex.printStackTrace(out);
} finally {
release();
}
}
/**
* 读取学科考试次数
* @return
*/
private int readExamCount() {
out.print("How many assessments are there for this subject?:");
return getValidNum();
}
/**
* 读取学生的一次考试成绩
* @return
*/
private int readMarkResult() {
out.print("Please enter assessment mark:");
return getValidNum();
}
/**
* 评估
* @throws Exception
*/
private void evaluate() throws Exception {
int count = evaluation.getAssignedCourseCount();
for (int k = 0; k < count; k++) {
out.println("\nCollecting information for subject "+k);
int times = readExamCount();
Course course = evaluation.getAssignedCourseAt(k);
course.assignExamTimes(times);
for (int i = 0; i < times; i++) {
int markResult = readMarkResult();
course.addMarkResult(markResult);
}
out.println("Subject Mark:"+course.evaluateSubject());
out.println();

}
out.println();
out.println();
out
.println("Student Average Mark is "
+ evaluation.getMarkingAverage());
}

private void release() {
if (reader != null) {
reader.close();
reader = null;
}
if (out != null) {
out.close();
out = null;
}
}
/**
*
* @return 获取评估课程数目
*/
private int readEvaluationCount() {
out.print("How many subjects are there?: ");
return getValidNum();
}
/**
* 从输入流中读取一个数值
* @return
*/
private int getValidNum() {
return reader.nextInt();
}

public static void main(String[] args) {
CourseApplication courseApplication = new CourseApplication();
courseApplication.play();

}
}
/**
*
* @author yaho
* 课程类
*/
class Course {

private int[] exams;
private int pos;
/**
* 返回考试总成绩
* @return
*/
public int getMarkingTotal() {
int total = 0;
for (int i = exams.length; --i >= 0;) {
total += exams[i];
}
return total;
}
/**
* 分配考试次数
* @param times
*/
public void assignExamTimes(int times) {
if (times < 0)
throw new IllegalArgumentException(
"Times of exam is negative number:" + times);
exams = new int[times];
}
/**
* 添加考试成绩
* @param res
*/
public void addMarkResult(int res) {
if(res<0||res>100)
throw new IllegalArgumentException("Mark value of exam out of bounds:"+res);
if (pos >= exams.length)
throw new IllegalStateException();
exams[pos++] = res;
}
/**
*
* @return 对该课程考试进行评估
*/
public String evaluateSubject() {
int total = getMarkingTotal();
StringBuilder ret = new StringBuilder();
ret.append(total);
ret.append(" - ");
if(total<50){
ret.append("NN");
}else if(total<=59){
ret.append("PA");
}else if(total<=69){
ret.append("CR");
}else if(total<=79){
ret.append("DI");
}else
ret.append("HD");

return ret.toString();
}

}
/**
*
* @author yaho
* 学生成绩评估类
*/
class CourseEvaluation {
/**
* 评估课程
*/
private Course[] courses = null;
/**
*
* @return
* 获取所有科目的平均成绩
*/
public int getMarkingAverage() {
int total = 0;
for (int i = courses.length; --i >= 0;) {
Course course = courses[i];
total += course == null ? 0 : course.getMarkingTotal();
}
return (int)(total/2f+0.5f);
}
/**
* 分配评估课程数目
* @param count
*/
public void assignCourseCount(int count) {
if (count < 0)
throw new IllegalArgumentException("Count is negative number:"
+ count);
if (count == 0)
throw new IllegalArgumentException(
"The count of evaluation must be a positive number!");
courses = new Course[count];
}
/**
* 获取评估课程数目
* @return
*/
public int getAssignedCourseCount() {
return courses.length;
}
/**
* 根据索引获取课程
* @param index
* @return
*/
public Course getAssignedCourseAt(int index) {
if (courses[index] == null)
courses[index] = new Course();
return courses[index];
}
}