public T GetElem(int i)
{
if (IsEmpty() || i < 0)
{
Console.WriteLine("DoubleLinkedList is empty or position is error");
return(default(T));
}
if (i == 1)
{
return(Head.Data);
}
DbNode <T> current = Head;
int j = 1;
while (current.Next != null && j < i)
{
current = current.Next;
j++;
}
if (j != i)
{
Console.WriteLine("Position is error");
return(default(T));
}
return(current.Data);
}
public void Append(T item)
{
if (IsEmpty())
{
Head = new DbNode <T>(item, null, null);
count = 1;
}
else
{
DbNode <T> current = Head;
while (current.Next != null)
{
current = current.Next;
}
current.Next = new DbNode <T>(item, current, null);
}
}
public void Insert(T item, int i)
{
if (IsEmpty() || i < 1)
{
Console.WriteLine("DbLinkedList is empty or Position is error!");
return;
}
//在最开头插入
if (i == 1)
{
DbNode <T> q = new DbNode <T>(item, null, null);
q.Next = Head; //把"头"改成第二个元素
Head.Prev = q;
Head = q; //把自己设置为"头"
count++;
return;
}
DbNode <T> n = Head;
DbNode <T> d = new DbNode <T>();
int j = 1;
//找到位置i的前一个元素d
while (n.Next != null && j < i)
{
d = n;
n = n.Next;
j++;
}
if (j == i)
{
DbNode <T> q = new DbNode <T>(item);
d.Next = q;
q.Prev = d;
q.Next = n;
n.Prev = q;
}
else
{
Append(item);
}
count++;
}
public int Locate(T value)
{
if (IsEmpty())
{
Console.WriteLine("DoubleLinkedList is empty");
return(-1);
}
DbNode <T> current = Head;
int j = 1;
do
{
if (current.Data.Equals(value))
{
return(j);
}
j++;
current = current.Next;
} while (current.Next != null);
return(-1);
}
public T Delete(int i)
{
if (IsEmpty() || i < 0)
{
Console.WriteLine("DoubleLinkedList is empty or position is error");
return(default(T));
}
if (i == 1)
{
T temp1 = Head.Data;
Head = null;
return(temp1);
}
DbNode <T> current = Head;
int j = 1;
while (current.Next != null && j < i)
{
current = current.Next;
j++;
}
if (j != i)
{
Console.WriteLine("Position is error");
return(default(T));
}
T temp = current.Data;
DbNode <T> prev = current.Prev;
prev.Next = current.Next;
DbNode <T> next = current.Next;
if (next != null)
{
next.Prev = prev;
}
return(temp);
}
//构造器
public DbNode(T val = default(T), DbNode <T> p = null, DbNode <T> n = null)
{
Data = val;
Prev = p;
Next = n;
}
} //后继引用域
//构造器
public DbNode( )
{
Data = default(T);
Prev = null;
Next = null;
}
public void Clear( )
{
Head = null;
count = 0;
}
public DoubleLinkedList(DbNode <T> node)
{
Head = node;
count = 1;
}
public DoubleLinkedList(T data)
{
Head = new DbNode <T>(data, null, null);
count = 1;
}
public DoubleLinkedList( )
{
Head = null;
count = 0;
}
