在锯齿阵列中总结数值

Question

我有一个锯齿阵列来获取学生和主题的详细信息，我使用了2个锯齿阵列，一个用于学生的详细信息（名称和rollno），另一个用于主题的详细信息（主题和标记），现在我想总结一下特定学生的所有标记，谁能告诉我怎么去解决这个问题，下面是我的整个代码。

public void GetStudentDetails() 
     { 

      Console.WriteLine("Please enter number of Students"); 
      int STUDENTS = Convert.ToInt32(Console.ReadLine()); 
      Console.WriteLine("Please enter number of Subjects"); 
      int SUBJECTS = Convert.ToInt32(Console.ReadLine()); //0 is reserved for the student name, so the marks starts from the index 1, hence if you set the marks for 3, it will ask for 2 marks 


      string[][] student_details = new string[STUDENTS][]; 
      string[][] subject_details = new string[SUBJECTS][]; 
      string[][] result_details = new string[STUDENTS][]; 

      StringBuilder stud_sub_info = new StringBuilder(); 
      stud_sub_info.Append("Name\tRoll-No\t"); 
      for (int a = 0; a < STUDENTS; a++) 
      { 
       student_details[a] = new string[STUDENTS * 2]; 
       for (int b = 0; b < 2; b++) 
       { 
        Console.WriteLine("Enter Student {0} {1}:", a + 1, (b == 0) ? "Name" : "Roll-No"); 
        student_details[a][b] = Console.ReadLine(); 
       } 
       for (int c = 0; c < SUBJECTS; c++) 
       { 
        subject_details[c] = new string[SUBJECTS * 2]; 
        for (int d = 0; d < 2; d++) 
        { 
         if (d == 0) 
         { 
          Console.WriteLine("Enter Name for Subject {0}", c + 1); 
          subject_details[c][d] = Console.ReadLine(); 
          stud_sub_info.Append(subject_details[c][d] + "\t"); 
         } 
         else 
         { 
          Console.WriteLine("Enter Marks for {0}", subject_details[c][d - 1]); 
          subject_details[c][d] = Console.ReadLine(); 
         } 
        } 
       } 
      } 
      Console.WriteLine(stud_sub_info.ToString()); 
      for (int a = 0; a < STUDENTS; a++) 
      { 
       for (int b = 0; b < 2; b++) 
       { 
        Console.Write(student_details[a][b] + "\t"); 
       } 
       for (int c = 0; c < SUBJECTS; c++) 
       { 
        for (int d = 0; d < 2; d++) 
        { 
         Console.Write(subject_details[c][d] + "\t"); 
        } 
       } 
      } 
     } 

Answer 1

我当然不会使用这样的锯齿状数组。它使编码困难。

例如，在您的代码中，您正在为每个学生捕获主题标记，但是当您清除之前学生的数据时。 subject_details交错排列的数组没有学生的索引。随时随地覆盖数据。您需要将该阵列声明为string[][][]。

这里是你的代码，更简单，将工作：

string[][] student_details = new string[STUDENTS][]; 
string[][][] subject_details = new string[STUDENTS][][]; 
string[][] result_details = new string[STUDENTS][]; 

for (int a = 0; a < STUDENTS; a++) 
{ 
    student_details[a] = new string[STUDENTS * 2]; 
    subject_details[a] = new string[SUBJECTS][]; 
    Console.WriteLine("Enter Student {0} {1}:", a + 1, "Name"); 
    student_details[a][0] = Console.ReadLine(); 
    Console.WriteLine("Enter Student {0} {1}:", a + 1, "Roll-No"); 
    student_details[a][1] = Console.ReadLine(); 
    for (int c = 0; c < SUBJECTS; c++) 
    { 
     subject_details[a][c] = new string[SUBJECTS * 2]; 
     Console.WriteLine("Enter Name for Subject {0}", c + 1); 
     subject_details[a][c][0] = Console.ReadLine(); 
     Console.WriteLine("Enter Marks for {0}", subject_details[a][c][0]); 
     subject_details[a][c][1] = Console.ReadLine(); 
    } 
} 
for (int a = 0; a < STUDENTS; a++) 
{ 
    Console.Write(student_details[a][0] + "\t"); 
    Console.Write(student_details[a][1] + "\t"); 
    for (int c = 0; c < SUBJECTS; c++) 
    { 
     Console.Write(subject_details[a][c][0] + "\t"); 
     Console.Write(subject_details[a][c][1] + "\t"); 
    } 
} 

现在因为我们忽略了这一事实，每一个学生都必须有相同数量的科目和您允许的非数字进入主题分数，你可以使用下面的LINQ查询将锯齿状的数组变成可行的。

var query = 
    from i in Enumerable.Range(0, STUDENTS) 
    let Name = student_details[i][0] 
    let RollNo = student_details[i][1] 
    let Subjects = (
     from j in Enumerable.Range(0, SUBJECTS) 
     let Subject = subject_details[i][j][0] 
     let Marks = int.Parse(subject_details[i][j][1]) 
     select new { Subject, Marks } 
    ) 
    select new { Name, RollNo, Subjects }; 

这让我看起来像这样的结构：

现在你可以使用这个查询来获取占总分：

var results = 
    query 
     .Select(x => new 
     { 
      x.Name, 
      TotalMarks = x.Subjects.Sum(y => y.Marks) 
     }); 

现在这个样子：

Answer 2

使用Linq，Collections和创建类而不是参差不齐的数组会更容易。这将允许你将1个学生连接到许多课程，并且在每门课程中都有许多作业。然后LINQ的语句如：

Sum(x => x.StudentGrade) 

下面是什么，我会在开始时只是为了得到什么，我可以用资金做一个想法存根复印件，以及其他信息：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Threading.Tasks; 

namespace StudentManagement { 
    public class Student { 

    public static void Main(string[] args) { 
     List<Student> students = new List<Student>(); 

     Console.Write("Enter number of students: "); 
     int numStudents = int.Parse(Console.ReadLine()); 

     for (int i = 0; i < numStudents; i++) { 
     Student s = new Student(); 
     students.Add(s); 
     } 

     Console.Write("Press any key to continue..."); 
     Console.ReadKey(true); 
    } 

    public string FirstName { get; set; } 
    public List<Course> Courses { get; set; } 

    public Student() { 
     this.Courses = new List<Course>(); 

     Console.Write("Enter First Name: "); 
     this.FirstName = Console.ReadLine(); 

     Console.Write("Enter in number of courses: "); 
     int numCourses = int.Parse(Console.ReadLine()); 

     for (int i = 0; i < numCourses; i++) { 
     Course course = new Course(); 
     this.Courses.Add(course); 
     } 

    } 
    } 

    public class Course { 
    public string Title { get; set; } 
    public string Code { get; set; } 
    public string Section { get; set; } 
    public List<Assignment> Assignments { get; set; } 

    public Course() { 
     this.Assignments = new List<Assignment>(); 

     // Set Title, Code, Section 
     Console.Write("Enter nuber of assignments: "); 
     int numAssignments = int.Parse(Console.ReadLine()); 

     for (int i = 0; i < numAssignments; i++) { 
     Assignment assignment = new Assignment(); 
     this.Assignments.Add(assignment); 
     } 

    } 
    } 

    public class Assignment { 
    public string Name { get; set; } 
    public double MaxGrade { get; set; } 
    public double StudentGrade { get; set; } 

    public Assignment() { 
     // Prompt for Name, MaxGrade, StudentGrade 
    } 
    } 
}