Thursday, 30 March 2017
New Class in C++ Biginteger Library!
I've started developing a C++ wrapper for GMP - high precision arithemtic library in C; updates on github today - bigrationals added! Only basic functions for now, but development in progress:)
Thursday, 23 March 2017
C++ GMP Wrapper
Recently beeing busy - writing, in C++, wrapper for GMP Library. Code here - you are invited to improve it!:)
Wednesday, 8 March 2017
Scala Trees
Recently, I've been playing with functional programming, ADT to be precise, and this is the outcome - trees implementation in Scala.
Data are created in common way as a Scala trait:
All looks Okay, lets create some trees and functions.
No problem, but at least for integer binary trees, we can right now do better: create a function to join elements to the tree:
This is the standard way to add elements to a binary tree, we can use it in a loop and don't need to worry about memory - we use persistent data structure.
Two sample functions operate on a tree:
They do what their names promise: count nodes and maximum depth of the trees. Finally map over the tree:
Data are created in common way as a Scala trait:
sealed trait Tree[+A] case object EmptyTree extends Tree[Nothing] case class Node[A](value: A, left: Tree[A], right: Tree[A]) extends Tree[A]
All looks Okay, lets create some trees and functions.
val tree = Node(10, Node(5, EmptyTree, EmptyTree), Node(15, EmptyTree, EmptyTree))
No problem, but at least for integer binary trees, we can right now do better: create a function to join elements to the tree:
def addToTree(elem: Int, tree: Tree[Int]): Tree[Int] = { if (isTreeEmpty(tree)) Node(elem, EmptyTree, EmptyTree) else if (elem == loadTree(tree)) tree else if (elem < loadTree(tree)) Node(loadTree(tree), addToTree(elem, leftBranch(tree)), rightBranch(tree)) else Node(loadTree(tree), leftBranch(tree), addToTree(elem, rightBranch(tree))) }
This is the standard way to add elements to a binary tree, we can use it in a loop and don't need to worry about memory - we use persistent data structure.
Two sample functions operate on a tree:
def length[A](tree: Tree2[A]): Int = tree match { case EmptyTree => 0 case Node(x, left, right) => length2(left) + 1 + length2(right) }
def maxDepth[A](tree: Tree2[A]): Int = tree match { case EmptyTree => 0 case Node(x, left, right) => var lmax = maxDepth2(left) var rmax = maxDepth2(right) if (lmax > rmax) lmax + 1 else rmax + 1 }
They do what their names promise: count nodes and maximum depth of the trees. Finally map over the tree:
def treeMap[A, B](tree: Tree2[A])(f: A => B): Tree2[B] = tree match { case EmptyTree => EmptyTree case Node(x, left, right) => Node(f(x), tree2Map(left)(f), tree2Map(right)(f)) }We can, in a similar way, all the needed function like foldl, traversing a tree and more. Code, including not implemented here functions helped to design joining element to tree, as usually on github. Till the next time!
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