基于C#双向循环链表的医院数据管理：患者关联信息输出问题

现有基于双向循环链表的医院数据管理代码，仅能查询并展示患者基本信息，无法关联显示患者对应的主治医生、用药记录及患病信息。以下是具体改造步骤及完整代码：

一、扩展双向循环链表的查询能力 #

原DoublyLinkedCircularList<T>类的QueryById仅能返回单个匹配项，无法满足药品这类一个患者对应多条记录的场景，需添加批量查询方法：

public IEnumerable<T> QueryAllById(Func<T, bool> query)
{
    if (Head == null)
        yield break;

    Node<T> current = Head;
    do
    {
        if (query(current.ID!))
            yield return current.ID!;

        current = current.Next!;
    } while (current != Head);
}

二、调整主程序查询逻辑，关联展示信息 #

在找到目标患者后，通过患者ID在医生、药品、疾病链表中查询对应记录，并分模块输出：

修改Main方法中的查询结果处理部分：

if (queriedPatient != null)
{
    Console.WriteLine($"=== 患者信息 ===");
    Console.WriteLine($"ID: {queriedPatient.ID}, 姓名: {queriedPatient.FirstName} {queriedPatient.LastName}");

    // 查询关联医生
    Console.WriteLine("\n=== 主治医生 ===");
    Doctor? assignedDoctor = doctorList.QueryById(doc => doc.ID == ID);
    if (assignedDoctor != null)
        Console.WriteLine(assignedDoctor.ToString());
    else
        Console.WriteLine("未关联医生");

    // 查询关联药品
    Console.WriteLine("\n=== 用药记录 ===");
    var patientMedicines = medicineList.QueryAllById(med => med.ID == ID);
    if (patientMedicines.Any())
        foreach (var med in patientMedicines)
            Console.WriteLine(med.ToString());
    else
        Console.WriteLine("无用药记录");

    // 查询关联疾病
    Console.WriteLine("\n=== 患病信息 ===");
    Disease? patientDisease = diseaseList.QueryById(dis => dis.ID == ID);
    if (patientDisease != null)
        Console.WriteLine(patientDisease.ToString());
    else
        Console.WriteLine("无患病记录");
}
else
{
    Console.WriteLine("未找到患者");
}

三、完整修改后代码 #

using System;
using System.Collections.Generic;
using System.Linq;

// Patient class
public class Patient
{
    public long? ID { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public Patient? Previous { get; set; }
    public Patient? Next { get; set; }

    public override string ToString()
    {
        return $"{ID}. {FirstName} {LastName}";
    }
}

// Medicine class
public class Medicine
{
    public long? ID { get; set; }
    public string Name { get; set; }
    public Medicine? Previous { get; set; }
    public Medicine? Next { get; set; }

    public override string ToString()
    {
        return $"{ID}. {Name}";
    }
}

// Doctor class
public class Doctor
{
    public long ID { get; set; }
    public string Name { get; set; }
    public string Specialty { get; set; }
    public Doctor? Previous { get; set; }
    public Doctor? Next { get; set; }

    public override string ToString()
    {
        return $"{ID}. {Name} ({Specialty})";
    }
}

// Disease class
public class Disease
{
    public long ID { get; set; }
    public string Name { get; set; }
    public Disease? Previous { get; set; }
    public Disease? Next { get; set; }

    public override string ToString()
    {
        return $"{ID}. {Name}";
    }
}

// Doubly linked circular list class
public class Node<T>
{
    public T? ID { get; set; }
    public Node<T>? Previous { get; set; }
    public Node<T>? Next { get; set; }
}

public class DoublyLinkedCircularList<T>
{
    private Node<T>? Head;

    public void Add(T element)
    {
        Node<T> newNode = new Node<T> { ID = element };

        if (Head == null)
        {
            Head = newNode;
            Head.Previous = Head;
            Head.Next = Head;
        }
        else
        {
            newNode.Previous = Head.Previous;
            newNode.Next = Head;
            Head.Previous!.Next = newNode;
            Head.Previous = newNode;
        }
    }

    public T? QueryById(Func<T, bool> query)
    {
        if (Head == null)
            return default;

        Node<T> current = Head;
        do
        {
            if (query(current.ID!))
                return current.ID;

            current = current.Next!;
        } while (current != Head);

        return default;
    }

    // 新增批量查询方法，返回所有匹配项
    public IEnumerable<T> QueryAllById(Func<T, bool> query)
    {
        if (Head == null)
            yield break;

        Node<T> current = Head;
        do
        {
            if (query(current.ID!))
                yield return current.ID!;

            current = current.Next!;
        } while (current != Head);
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Doubly linked circular lists
        DoublyLinkedCircularList<Patient> patientList = new DoublyLinkedCircularList<Patient>();
        DoublyLinkedCircularList<Medicine> medicineList = new DoublyLinkedCircularList<Medicine>();
        DoublyLinkedCircularList<Doctor> doctorList = new DoublyLinkedCircularList<Doctor>();
        DoublyLinkedCircularList<Disease> diseaseList = new DoublyLinkedCircularList<Disease>();

        // Add sample data
        patientList.Add(new Patient { ID = 46573806740, FirstName = "Hiranur", LastName = "Sazak" });
        patientList.Add(new Patient { ID = 23746982347, FirstName = "Nisa Nur", LastName = "Özdal" });
        patientList.Add(new Patient { ID = 89374938243, FirstName = "Nisa Gül", LastName = "Ünal" });
        patientList.Add(new Patient { ID = 98723424674, FirstName = "Berfin", LastName = "Geleş" });

        medicineList.Add(new Medicine { ID = 46573806740, Name = "Theraflu Forte" });
        medicineList.Add(new Medicine { ID = 46573806740, Name = "Ketober %1.6 Gargara" });
        // ... (add more medicines)

        doctorList.Add(new Doctor { ID = 46573806740, Name = "Dr. Ömer Kaplan", Specialty = "Ear, Nose, Throat" });
        doctorList.Add(new Doctor { ID = 23746982347, Name = "Dr. Ali Nazmican Güröz ", Specialty = "Orthopedics" });
        // ... (add more doctors)

        diseaseList.Add(new Disease { ID = 46573806740, Name = "Cold" });
        diseaseList.Add(new Disease { ID = 23746982347, Name = "Meniscus Tear" });
        // ... (add more diseases)

        Console.WriteLine("\n...ID 查询...");

        Console.Write("请输入ID编号: ");
        if (long.TryParse(Console.ReadLine(), out long ID))
        {
            Patient? queriedPatient = patientList.QueryById(patient => patient.ID == ID);

            if (queriedPatient != null)
            {
                Console.WriteLine($"=== 患者信息 ===");
                Console.WriteLine($"ID: {queriedPatient.ID}, 姓名: {queriedPatient.FirstName} {queriedPatient.LastName}");

                // 查询关联医生
                Console.WriteLine("\n=== 主治医生 ===");
                Doctor? assignedDoctor = doctorList.QueryById(doc => doc.ID == ID);
                if (assignedDoctor != null)
                    Console.WriteLine(assignedDoctor.ToString());
                else
                    Console.WriteLine("未关联医生");

                // 查询关联药品
                Console.WriteLine("\n=== 用药记录 ===");
                var patientMedicines = medicineList.QueryAllById(med => med.ID == ID);
                if (patientMedicines.Any())
                    foreach (var med in patientMedicines)
                        Console.WriteLine(med.ToString());
                else
                    Console.WriteLine("无用药记录");

                // 查询关联疾病
                Console.WriteLine("\n=== 患病信息 ===");
                Disease? patientDisease = diseaseList.QueryById(dis => dis.ID == ID);
                if (patientDisease != null)
                    Console.WriteLine(patientDisease.ToString());
                else
                    Console.WriteLine("无患病记录");
            }
            else
            {
                Console.WriteLine("未找到患者");
            }
        }
        else
        {
            Console.WriteLine("输入的ID编号无效");
        }
        Console.ReadKey();
    }
}

改造说明 #

1. 新增QueryAllById方法，支持从链表中获取所有匹配指定条件的记录，适配一个患者对应多条药品记录的场景。
2. 调整主程序的查询输出逻辑，在获取患者信息后，通过相同ID关联查询医生、药品、疾病数据，并分模块展示。
3. 界面输出优化为中文，更符合使用习惯。

内容的提问来源于stack exchange，提问作者Meral Hamarat