/// <summary>
/// 迭代器
/// </summary>
/// <returns></returns>
public IEnumerator GetEnumerator()
{
SparseArrayCell <T> current = _head;
if (current == null)
{
yield return(_notSetVal);
}
else
{
do
{
yield return(current.Val);
}while ((current = current.Next) != null);
}
}
/// <summary>
/// 把元素追加到尾部
/// </summary>
/// <param name="val">数据</param>
/// <param name="index">下标</param>
public void AppendToTail(T val, int index)
{
SparseArrayCell <T> newCell = new SparseArrayCell <T>
{
Val = val,
Index = index,
Prev = _tail
};
if (_tail == null)
{
_head = newCell;
}
else
{
_tail.Next = newCell;
}
_tail = newCell;
}
/// <summary>
/// 读写稀疏数组的值
/// </summary>
/// <param name="index"></param>
/// <returns></returns>
public T this[int index]
{
set
{
if (value == null || value.Equals(_notSetVal))
{
return;
}
if (index >= Length || index < 0)
{
throw new Exception($"稀疏数组长度为{Length}，超出范围。");
}
SparseArrayCell <T> newCell = new SparseArrayCell <T>
{
Index = index,
Val = value,
};
_indexMap[index] = value;
SparseArrayCell <T> current = _head;
if (current == null)
{
_tail = _head = new SparseArrayCell <T> {
Index = index, Val = value
};
return;
}
bool nearHead = (index << 1) < _tail.Index + _head.Index;
if (nearHead)
{
current = _head;
while (true)
{
if (current.Index == index)
{
current.Val = value;
return;
}
else if (current.Index < index)
{
if (current.Next == null)
{
newCell.Prev = current;
_tail = current.Next = newCell;
return;
}
else
{
current = current.Next;
}
}
else if (current.Index > index)
{
if (current.Prev == null)
{
newCell.Next = current;
_head = current.Prev = newCell;
}
else
{
newCell.Prev = current.Prev;
newCell.Next = current;
current.Prev = current.Prev.Next = newCell;
}
return;
}
}
}
else
{
current = _tail;
while (true)
{
if (current.Index == index)
{
current.Val = value;
return;
}
else if (current.Index > index)
{
if (current.Prev == null)
{
newCell.Next = current;
_head = current.Prev = newCell;
return;
}
else
{
current = current.Prev;
}
}
else if (current.Index < index)
{
if (current.Next == null)
{
newCell.Prev = current;
_tail = current.Next = newCell;
}
else
{
newCell.Prev = current;
newCell.Next = current.Next;
current.Next = current.Next.Prev = newCell;
}
return;
}
}
}
}
get
{
if (index >= Length || index < 0)
{
throw new Exception($"稀疏数组长度为{Length}，超出范围。");
}
T val;
_indexMap.TryGetValue(index, out val);
return(val);
//SparseArrayCell<T> current = _head;
//if (current == null)
//{
// return _notSetVal;
//}
//bool nearHead = (index << 1) < _tail.Index + _head.Index;
//if (nearHead)
//{
// current = _head;
// while (true)
// {
// if (current.Index == index)
// {
// return current.Val;
// }
// else if (current.Index< index)
// {
// current=current.Next;
// }
// else if (current.Index > index)
// {
// return _notSetVal;
// }
// }
//}
//else
//{
// current = _tail;
// while (true)
// {
// if (current.Index == index)
// {
// return current.Val;
// }
// else if (current.Index > index)
// {
// current = current.Prev;
// }
// else if (current.Index < index)
// {
// return _notSetVal;
// }
// }
//}
}
}
