mirrors/bitcoin-s
1
0
Fork 0
mirror of https://github.com/bitcoin-s/bitcoin-s.git synced 2025-01-18 21:34:39 +01:00
Code Issues Packages Projects Releases Wiki Activity

Optimizing findFirstDfs to a tail recursive function

Browse Source
This commit is contained in:
Chris Stewart 2016-02-20 12:44:46 -06:00
parent ad7383bac5
commit a94fe6393f
1 changed files with 12 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
src/main/scala/org/scalacoin/util/BinaryTree.scala
View File

@ -51,14 +51,17 @@ trait BinaryTree[+T] {
* @return * @return
*/ */
def findFirstDFS[T](t : T)(f : T => Boolean = (x : T) => x == t)(implicit tree : BinaryTree[T] = this) : Option[BinaryTree[T]] = { def findFirstDFS[T](t : T)(f : T => Boolean = (x : T) => x == t)(implicit tree : BinaryTree[T] = this) : Option[BinaryTree[T]] = {
//TODO: Optimize this to be tail recursive @tailrec
if (tree.value.isDefined && f(tree.value.get)) Some(tree) def loop(subTree : BinaryTree[T], remainder : List[BinaryTree[T]]) : Option[BinaryTree[T]] = {
else { subTree match {
val leftTreeResult : Option[BinaryTree[T]] = if (tree.left.isDefined) findFirstDFS(t)(f)(tree.left.get) else None case Empty => if (remainder.isEmpty) None else loop(remainder.head, remainder.tail)
if (leftTreeResult.isDefined) leftTreeResult case Leaf(x) => if (f(x)) Some(Leaf(x)) else if (remainder.isEmpty) None else loop(remainder.head, remainder.tail)
else if (tree.right.isDefined) findFirstDFS(t)(f)(tree.right.get) case Node(v, l, r) =>
else None if (f(v)) Some(Node(v,l,r))
else loop(l, r :: remainder)
}
} }
loop(tree,List())
} }
@ -94,7 +97,7 @@ trait BinaryTree[+T] {
* if it cannot insert it because the branches are not empty * if it cannot insert it because the branches are not empty
* it throws a runtime exception * it throws a runtime exception
* @param subTree * @param subTree
* @param tree * @param parentTree
* @tparam T * @tparam T
* @return * @return
*/ */
@ -108,6 +111,7 @@ trait BinaryTree[+T] {
} }
def remove[T](subTree : BinaryTree[T])(parentTree : BinaryTree[T] = this) : BinaryTree[T] = { def remove[T](subTree : BinaryTree[T])(parentTree : BinaryTree[T] = this) : BinaryTree[T] = {
//TODO: Optimize into a tail recursive function //TODO: Optimize into a tail recursive function
parentTree match { parentTree match {
@ -128,7 +132,6 @@ trait BinaryTree[+T] {
* @return * @return
*/ */
def replace[T](originalTree : BinaryTree[T], replacement : BinaryTree[T])(implicit parentTree : BinaryTree[T] = this) : BinaryTree[T] = { def replace[T](originalTree : BinaryTree[T], replacement : BinaryTree[T])(implicit parentTree : BinaryTree[T] = this) : BinaryTree[T] = {
parentTree match { parentTree match {
case Empty => Empty case Empty => Empty
case l : Leaf[T] => if (l == originalTree) replacement else l case l : Leaf[T] => if (l == originalTree) replacement else l