redef type N: BinTreeNode[K, E]
private var len = 0
+ private var first_node: nullable BinTreeNode[K, E] = null
+ private var last_node: nullable BinTreeNode[K, E] = null
# O(n) in worst case, average is O(h) with h: tree height
#
# tree[1] = "n1"
# assert not tree.is_empty
redef fun is_empty do return root == null
+
+ # O(n) in worst case, average is O(h) with h: tree height
+ #
+ # var tree = new BinTreeMap[Int, String]
+ # assert not tree.has_key(1)
+ # for i in [4, 2, 1, 5, 3] do tree[i] = "n{i}"
+ # assert not tree.has_key(0)
+ # assert tree.has_key(2)
+ # assert not tree.has_key(6)
+ redef fun has_key(key: K): Bool do
+ if is_empty then return false
+ var res = search_down(root.as(not null), key)
+ if res != null then
+ cache_node = res
+ return true
+ end
+ return false
+ end
+
+ private var cache_node: nullable N = null
+
# Get the node value associated to `key`
# O(n) in worst case, average is O(h) with h: tree height
#
# var tree = new BinTreeMap[Int, String]
# for i in [4, 2, 1, 5, 3] do tree[i] = "n{i}"
+ # assert tree.has_key(1)
# assert tree[1] == "n1"
+ # assert tree.has_key(1)
+ # assert tree[2] == "n2"
redef fun [](key: K): E do
- assert not_empty: root != null
+ assert not_empty: not is_empty
+ if cache_node != null and cache_node.key == key then return cache_node.value
var res = search_down(root.as(not null), key)
assert has_key: res != null
return res.value
end
protected fun search_down(from: N, key: K): nullable N do
- if key == from.key then return from
- if from.left != null and key < from.key then
+ var cmp = key <=> from.key
+ if cmp == 0 then return from
+ if from.left != null and cmp < 0 then
return search_down(from.left.as(not null), key)
else if from.right != null then
return search_down(from.right.as(not null), key)
else
shift_down(root.as(not null), node)
end
+ if first_node == null then
+ first_node = node
+ end
+ if last_node != null then
+ last_node.next = node
+ node.prev = last_node
+ end
+ last_node = node
end
# Push down the `node` in tree from a specified `from` index
protected fun shift_down(from, node: N) do
- if node.key < from.key then
+ var cmp = node.key <=> from.key
+ if cmp < 0 then
if from.left == null then
from.left = node
node.parent = from
else
shift_down(from.left.as(not null), node)
end
- else if node.key > from.key then
+ else if cmp > 0 then
if from.right == null then
from.right = node
node.parent = from
min.left = node.left
min.left.parent = min
end
+ if first_node == node then
+ first_node = null
+ end
+ if last_node == node then
+ last_node = node.prev
+ last_node.next = null
+ else
+ node.prev.next = node.next
+ node.next.prev = node.prev
+ end
return node.value
end
# for i in [4, 2, 1, 5, 3] do tree[i] = "n{i}"
# assert tree.length == 5
redef fun length do return len
+
+ # Nodes are iterated in the same order in which they were added to the tree.
+ # O(n)
+ #
+ # var tree = new BinTreeMap[Int, String]
+ # for i in [4, 2, 1, 5, 3] do tree[i] = "n{i}"
+ # var keys = new Array[Int]
+ # for k, v in tree do
+ # keys.add k
+ # end
+ # assert keys == [4, 2, 1, 5, 3]
+ redef fun iterator do return new BinTreeMapIterator[K, E](self)
end
# TreeNode used by BinTree
class BinTreeNode[K: Comparable, E]
super TreeNode[K, E]
+ private var prev: nullable BinTreeNode[K, E]
+ private var next: nullable BinTreeNode[K, E]
+
redef type SELF: BinTreeNode[K, E]
init(key: K, item: E) do
# set `left` child for this node (or null if left no child)
# ENSURE: node.key < key (only if node != null)
fun left=(node: nullable SELF) do
- assert node != null implies node.key < key
+ #assert node != null implies node.key < key
left_node = node
end
# set `right` child for this node (or null if right no child)
# ENSURE: node.key < key (only if node != null)
fun right=(node: nullable SELF) do
- if node != null then
- assert node.key > key
- end
+ #assert node != null implies node.key > key
right_node = node
end
end
end
- redef fun to_s do return "\{{key}: {value}\}"
+ redef fun to_s do return "\{{key}: {value or else ""}\}"
end
+private class BinTreeMapIterator[K: Comparable, E]
+ super MapIterator[K, E]
+
+ var current: nullable BinTreeNode[K, E]
+
+ init(tree: BinTreeMap[K, E]) do
+ current = tree.first_node
+ end
+
+ redef fun is_ok do return not current == null
+ redef fun next do current = current.next
+ redef fun item do return current.value
+ redef fun key do do return current.key
+end
nitlanguage / nit.git / blobdiff