public override void Foreach(Action <TK, TV> action)
{
SkipNode <TK, TV> x = _header;
while (x.Forward[0] != null)
{
action(x.Key, x.Value);
}
}
public override bool Contains(TK key)
{
SkipNode <TK, TV> x = _header;
for (int i = MaxLevel; i >= 0; i--)
{
while (x.Forward[i] != null && x.Forward[i].Key.CompareTo(key) < 0)
{
x = x.Forward[i];
}
}
x = x.Forward[0];
return(x != null && x.Key.CompareTo(key) == 0);
}
protected override TV Get(TK key)
{
SkipNode <TK, TV> x = _header;
for (int i = _level; i >= 0; i--)
{
while (x.Forward[i] != null && x.Forward[i].Key.CompareTo(key) < 0)
{
x = x.Forward[i];
}
}
if (x.Forward[0].Key.CompareTo(key) == 0)
{
return(x.Forward[0].Value);
}
else
{
throw new ArgumentException("The Key was not found");
}
}
protected override bool Put(TK key, TV value)
{
SkipNode <TK, TV> x = _header;
SkipNode <TK, TV>[] update = new SkipNode <TK, TV> [MaxLevel + 1];
for (int i = _level; i >= 0; i--)
{
while (x.Forward[i] != null && x.Forward[i].Key.CompareTo(key) < 0)
{
x = x.Forward[i];
}
update[i] = x;
}
x = x.Forward[0];
if (x == null || x.Key.CompareTo(key) != 0)
{
int lvl = MathHelper.RandomLevel(MaxLevel);
if (lvl > _level)
{
for (int i = _level + 1; i <= lvl; i++)
{
update[i] = _header;
}
_level = lvl;
}
x = new SkipNode <TK, TV>(lvl, key, value);
_size++;
for (int i = 0; i <= lvl; i++)
{
x.Forward[i] = update[i].Forward[i];
update[i].Forward[i] = x;
}
}
if (x.Key.CompareTo(key) == 0)
{
x.Value = value;
}
return(true);
}
public override TV Remove(TK key)
{
SkipNode <TK, TV> x = _header;
SkipNode <TK, TV>[] updateNode = new SkipNode <TK, TV> [MaxLevel + 1];
for (int i = _level; i >= 0; i--)
{
while (x.Forward[i] != null && x.Forward[i].Key.CompareTo(key) < 0)
{
x = x.Forward[i];
}
updateNode[i] = x;
}
x = x.Forward[0];
if (x.Key.CompareTo(key) == 0)
{
for (int i = 0; i <= _level; i++)
{
if (updateNode[i].Forward[i] != x)
{
break;
}
updateNode[i].Forward[i] = x.Forward[i];
}
while (_level > 0 && _header.Forward[_level] == null)
{
_level--;
}
_size--;
}
else
{
throw new ArgumentException("The Key was not found");
}
return(x.Value);
}
public SkipListDictionary()
{
_header = new SkipNode <TK, TV>(MaxLevel);
_level = 0;
_size = 0;
}
