C#，《小白学程序》第十一课：双向链表(Linked-List)其二，链表的插入与删除的方法（函数）与代码

1 文本格式

/// <summary>
/// 改进的车站信息类 class
/// 增加了链表需要的两个属性 Last Next
/// </summary>
public class StationAdvanced
{
/// <summary>
/// 编号
/// </summary>
public int Id { get; set; } = 0;
/// <summary>
/// 车站名
/// </summary>
public string Name { get; set; } = string.Empty;
public StationAdvanced Last { get; set; } = null;
public StationAdvanced Next { get; set; } = null;

public StationAdvanced(int id, string name)
{
this.Id = id;
this.Name = name;
}
}

// 列表的初值
List<StationAdvanced> stations_advanced = new List<StationAdvanced>() {
new StationAdvanced(1,"北京"),
new StationAdvanced(2,"石家庄"),
new StationAdvanced(3,"香河"),
new StationAdvanced(4,"唐山"),
new StationAdvanced(5,"北戴河"),
new StationAdvanced(6,"秦皇岛"),
new StationAdvanced(7,"廊坊"),
new StationAdvanced(8,"天津"),
};

/// <summary>
/// 《小白学程序》第十三课：双向链表(Linked-List)第二，链表插入与删除的计算方法与代码
/// 本课是《小白学程序》第十课之续章。
/// 学习用函数来实现链表的（节点）插入、删除，而不是手工输入。
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button13_Click(object sender, EventArgs e)
{
StationAdvanced bj = stations_advanced[0];
StationAdvanced xh = stations_advanced[2];
StationAdvanced ts = stations_advanced[3];
StationAdvanced qhd = stations_advanced[5];

// #2 构造车次信息（直达）
// 设置北京下一站为秦皇岛
// 设置秦皇岛唐山上一站为北京
bj.Next = qhd;
qhd.Last = bj;

// 调用链表的插入删除算法
// 插入香河
StationInsert(bj, xh);
// 插入唐山
StationInsert(xh, ts);

// #4 输出车次信息(正向)
StringBuilder sb = new StringBuilder();
sb.AppendLine("插入新车站： ");
// 北京出发
StationAdvanced start = bj;
while (start != null)
{
sb.AppendLine(start.Id + " " + start.Name + " ");
start = start.Next;
}
sb.AppendLine(" ");

// 删除香河
StationRemove(xh);

// #4 输出车次信息(正向)
// 北京出发
sb.AppendLine("删除指定车站： ");
start = bj;
while (start != null)
{
sb.AppendLine(start.Id + " " + start.Name + " ");
start = start.Next;
}

webBrowser1.DocumentText = sb.ToString();
}

/// <summary>
/// 双向链表的插入算法
/// 将 c 节点插入 a （之后） b 之间
/// </summary>
/// <param name="a"></param>
/// <param name="c"></param>
private void StationInsert(StationAdvanced a, StationAdvanced c)
{
StationAdvanced b = a.Next;
a.Next = c;
c.Last = a;
c.Next = b;
b.Last = c;
}

/// <summary>
/// 双向链表的删除算法
/// 删除 a （之后）的 b 节点
/// </summary>
/// <param name="a"></param>
private void StationRemove(StationAdvanced b)
{
StationAdvanced a = b.Last;
StationAdvanced c = b.Next;
a.Next = c;
c.Last = a;
}

2 代码格式


/// <summary>
/// 改进的车站信息类 class
/// 增加了 链表 需要的两个属性 Last Next
/// </summary>
public class StationAdvanced
{
    /// <summary>
    /// 编号
    /// </summary>
    public int Id { get; set; } = 0;
    /// <summary>
    /// 车站名
    /// </summary>
    public string Name { get; set; } = string.Empty;
    public StationAdvanced Last { get; set; } = null;
    public StationAdvanced Next { get; set; } = null;

    public StationAdvanced(int id, string name)
    {
        this.Id = id;
        this.Name = name;
    }
}

// 列表的初值
List<StationAdvanced> stations_advanced = new List<StationAdvanced>() {
        new StationAdvanced(1,"北京"),
        new StationAdvanced(2,"石家庄"),
        new StationAdvanced(3,"香河"),
        new StationAdvanced(4,"唐山"),
        new StationAdvanced(5,"北戴河"),
        new StationAdvanced(6,"秦皇岛"),
        new StationAdvanced(7,"廊坊"),
        new StationAdvanced(8,"天津"),
};

/// <summary>
/// 《小白学程序》第十三课：双向链表(Linked-List)第二，链表插入与删除的计算方法与代码
/// 本课是《小白学程序》第十课之续章。
/// 学习用 函数 来实现 链表的（节点）插入、删除，而不是手工输入。
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button13_Click(object sender, EventArgs e)
{
    StationAdvanced bj = stations_advanced[0];
    StationAdvanced xh = stations_advanced[2];
    StationAdvanced ts = stations_advanced[3];
    StationAdvanced qhd = stations_advanced[5];

    // #2 构造车次信息（直达）
    // 设置 北京 下一站为 秦皇岛
    // 设置 秦皇岛唐山 上一站为 北京 
    bj.Next = qhd;
    qhd.Last = bj;

    // 调用链表的 插入 删除 算法
    // 插入香河
    StationInsert(bj, xh);
    // 插入唐山
    StationInsert(xh, ts);

    // #4 输出车次信息(正向)
    StringBuilder sb = new StringBuilder();
    sb.AppendLine("插入新车站：<br>");
    // 北京 出发
    StationAdvanced start = bj;
    while (start != null)
    {
        sb.AppendLine(start.Id + " " + start.Name + "<br>");
        start = start.Next;
    }
    sb.AppendLine("<br>");

    // 删除 香河
    StationRemove(xh);

    // #4 输出车次信息(正向)
    // 北京 出发
    sb.AppendLine("删除指定车站：<br>");
    start = bj;
    while (start != null)
    {
        sb.AppendLine(start.Id + " " + start.Name + "<br>");
        start = start.Next;
    }

    webBrowser1.DocumentText = sb.ToString();
}

/// <summary>
/// 双向链表的插入算法
/// 将 c 节点插入 a （之后） b 之间
/// </summary>
/// <param name="a"></param>
/// <param name="c"></param>
private void StationInsert(StationAdvanced a, StationAdvanced c)
{
    StationAdvanced b = a.Next;
    a.Next = c;
    c.Last = a;
    c.Next = b;
    b.Last = c;
}

/// <summary>
/// 双向链表的删除算法
/// 删除 a （之后） 的 b 节点
/// </summary>
/// <param name="a"></param>
private void StationRemove(StationAdvanced b)
{
    StationAdvanced a = b.Last;
    StationAdvanced c = b.Next;
    a.Next = c;
    c.Last = a;
}