private Treap(T key, int rank, Treap <T> left = null, Treap <T> right = null)
{
this.key = key;
this.rank = rank;
this.left = left;
this.right = right;
}
private void Split(T key, out Treap <T> left, out Treap <T> right)
{
Treap <T> newTree = null;
if (key.CompareTo(this.key) > 0)
{
if (this.right == null)
{
right = null;
}
else
{
this.right.Split(key, out newTree, out right);
}
left = new Treap <T>(this.key, this.rank, this.left, newTree);
}
else
{
if (this.left == null)
{
left = null;
}
else
{
this.left.Split(key, out left, out newTree);
}
right = new Treap <T>(this.key, this.rank, newTree, this.right);
}
}
public static IEnumerable <T> SortWithTreap(IEnumerable <T> keys)
{
Treap <T> treap = Treap <T> .Create(keys);
foreach (var number in treap.TraverseInOrder())
{
yield return(number);
}
}
public Treap <T> Add(T key, int rank)
{
Treap <T> left;
Treap <T> right;
Treap <T> keyTree = new Treap <T>(key, rank);
this.Split(key, out left, out right);
return(Merge(Merge(left, keyTree), right));
}
public static Treap <T> Create(IEnumerable <T> keys)
{
IEnumerator <T> enumerator = keys.GetEnumerator();
if (!enumerator.MoveNext())
{
return(null);
}
Random dice = new Random();
Treap <T> result = new Treap <T>(enumerator.Current, dice.Next());
while (enumerator.MoveNext())
{
result = result.Add(enumerator.Current, dice.Next());
}
return(result);
}
private static Treap <T> Merge(Treap <T> left, Treap <T> right)
{
if (left == null)
{
return(right);
}
if (right == null)
{
return(left);
}
if (left.rank > right.rank)
{
Treap <T> newRight = Merge(left.right, right);
return(new Treap <T>(left.key, left.rank, left.left, newRight));
}
else
{
Treap <T> newLeft = Merge(left, right.left);
return(new Treap <T>(right.key, right.rank, newLeft, right.right));
}
}
public static Treap <T> Search(Treap <T> tree, T key)
{
//NE TESTIL, DOLZHNO RABOTAT'
//If Key can't be found returns null
//otherwise returns treap containing that key
if (tree == null)
{
return(null);
}
if (tree.key.CompareTo(key) == 0)
{
return(tree);
}
if (tree.key.CompareTo(key) > 0)
{
return(Search(tree.left, key));
}
else
{
return(Search(tree.right, key));
}
}