带有扫描器输入Java作业问题

Question

import java.util.Scanner;

public class Find2Max {

    public void run() { 

            Scanner sc = new Scanner(System.in);
            System.out.print("Enter the number of at least 2 students: ");
            int number_of_students = sc.nextInt();

            if(number_of_students < 2){             
                    number_of_students = 2; 
            }

            do{

                    double top_grade = 0;  
                    double second_top_grade = 0; 
                    String top_kid = ""; 
                    String second_top_kid= ""; 

                    for(int ii = 0; ii < number_of_students; ii++){ 
                            System.out.print("Enter a student name: ");
                            String student_name = sc.nextLine(); 

                            System.out.print("Enter a student score: "); 
                            Double student_grade = sc.nextDouble(); 

                            if(student_grade > top_grade){
                                    top_kid = student_name;
                                    top_grade = student_grade; 
                            }
                            else if(student_grade > second_top_grade && student_grade < top_grade){
                                    second_top_grade = student_grade; 
                                    second_top_kid = student_name; 
                            }
                            else{
                                    student_grade = 0.00; 
                                    student_name =""; 
                            }      
                    }
                    System.out.println("Top two students: ");
                    System.out.println( top_kid + "'s score is " + top_grade);
                    System.out.println(second_top_kid + "'s score is " + second_top_grade);
            }while(number_of_students >= 2);              
    }

    public static void main(String[] args){
            Find2Max test = new Find2Max(); 
            test.run(); 
    }        
}

我努力解决问题，我真的很接近，但我很困惑为什么我的程序似乎跳过，没有读取输入学生姓名部分我的输入。当学生数为1时，似乎也有这个问题。任何帮助都将不胜感激！:]

Answer 1

原始代码有许多问题：

• 不能很好地处理线路转换
• 不处理第二名学生成绩高于第一名的情况
• 它不处理等级相等的角落情况

下面是一个稍微改进的版本，增加了一些额外的新行，使输出更易读。允许程序优雅地退出的一个修改是，如果提供的学生人数少于2人就退出，而不是人为地将人数设置为2人。第三条else语句被注释掉，因为不需要。

public class Find2Max {

  public void run() {
    Scanner sc = new Scanner(System.in);
    System.out.print("\nEnter the number of students (at least 2 required for comparison): ");
    int number_of_students = sc.nextInt();

    if(number_of_students < 2){
      System.out.println("\nThis program compares scores for 2 or more students.");
      // number_of_students = 2;
      return;
    }

    do{

      double top_grade = 0;
      double second_top_grade = 0;
      String top_kid = "";
      String second_top_kid= "";

      for(int ii = 0; ii < number_of_students; ii++){
        System.out.print("\nEnter a student name: ");
        String student_name = sc.next();

        System.out.print("Enter a student score: ");
        Double student_grade = sc.nextDouble();

        if(student_grade >= top_grade){
          if(top_grade >= second_top_grade) { // Save this grade as the second top
            second_top_kid = top_kid;
            second_top_grade = top_grade;
          }
          top_kid = student_name;
          top_grade = student_grade;
        }
        else if(student_grade > second_top_grade && student_grade < top_grade){
          second_top_grade = student_grade;
          second_top_kid = student_name;
        }
//        else{
//          student_grade = 0.00;
//          student_name ="";
//        }
      }
      System.out.println("\nTop two students: ");
      System.out.println( top_kid + "'s score is " + top_grade);
      System.out.println(second_top_kid + "'s score is " + second_top_grade);
    }while(number_of_students >= 2);
  }

  public static void main(String[] args){
    Find2Max test = new Find2Max();
    test.run();
  }
}