Updated playground to Swift 3

Binary Search Tree/Solution 1/BinarySearchTree.playground/Contents.swift

@@ -1,21 +1,21 @@
 //: Playground - noun: a place where people can play
 
 let tree = BinarySearchTree<Int>(value: 7)
-tree.insert(2)
-tree.insert(5)
-tree.insert(10)
-tree.insert(9)
-tree.insert(1)
+tree.insert(value: 2)
+tree.insert(value: 5)
+tree.insert(value: 10)
+tree.insert(value: 9)
+tree.insert(value: 1)
 
 tree
 tree.debugDescription
 
 let tree2 = BinarySearchTree<Int>(array: [7, 2, 5, 10, 9, 1])
 
-tree.search(5)
-tree.search(2)
-tree.search(7)
-tree.search(6)
+tree.search(value: 5)
+tree.search(value: 2)
+tree.search(value: 7)
+tree.search(value: 6)
 
 tree.traverseInOrder { value in print(value) }
 
@@ -24,7 +24,7 @@ tree.toArray()
 tree.minimum()
 tree.maximum()
 
-if let node2 = tree.search(2) {
+if let node2 = tree.search(value: 2) {
  node2.remove()
  node2
  print(tree)
@@ -34,25 +34,25 @@ tree.height()
 tree.predecessor()
 tree.successor()
 
-if let node10 = tree.search(10) {
+if let node10 = tree.search(value: 10) {
  node10.depth() // 1
  node10.height() // 1
  node10.predecessor()
  node10.successor() // nil
 }
 
-if let node9 = tree.search(9) {
+if let node9 = tree.search(value: 9) {
  node9.depth() // 2
  node9.height() // 0
  node9.predecessor()
  node9.successor()
 }
 
-if let node1 = tree.search(1) {
+if let node1 = tree.search(value: 1) {
  // This makes it an invalid binary search tree because 100 is greater
  // than the root, 7, and so must be in the right branch not in the left.
  tree.isBST(minValue: Int.min, maxValue: Int.max) // true
- node1.insert(100)
- tree.search(100) // nil
+ node1.insert(value: 100)
+ tree.search(value: 100) // nil
  tree.isBST(minValue: Int.min, maxValue: Int.max) // false
 }

Binary Search Tree/Solution 1/BinarySearchTree.playground/Sources/BinarySearchTree.swift

@@ -10,10 +10,10 @@
  you should insert new values in randomized order, not in sorted order.
 */
 public class BinarySearchTree<T: Comparable> {
- private(set) public var value: T
- private(set) public var parent: BinarySearchTree?
- private(set) public var left: BinarySearchTree?
- private(set) public var right: BinarySearchTree?
+ fileprivate(set) public var value: T
+ fileprivate(set) public var parent: BinarySearchTree?
+ fileprivate(set) public var left: BinarySearchTree?
+ fileprivate(set) public var right: BinarySearchTree?
 
  public init(value: T) {
  self.value = value
@@ -22,8 +22,8 @@ public class BinarySearchTree<T: Comparable> {
  public convenience init(array: [T]) {
  precondition(array.count > 0)
  self.init(value: array.first!)
- for v in array.dropFirst() {
- insert(v, parent: self)
+ for v in array.dropFirst() { 
+ insert(value: v, parent: self)
  }
  }
 
@@ -74,20 +74,20 @@ extension BinarySearchTree {
  Performance: runs in O(h) time, where h is the height of the tree.
  */
  public func insert(value: T) {
- insert(value, parent: self)
+ insert(value: value, parent: self)
  }
 
- private func insert(value: T, parent: BinarySearchTree) {
+ fileprivate func insert(value: T, parent: BinarySearchTree) {
  if value < self.value {
  if let left = left {
- left.insert(value, parent: left)
+ left.insert(value: value, parent: left)
  } else {
  left = BinarySearchTree(value: value)
  left?.parent = parent
  }
  } else {
  if let right = right {
- right.insert(value, parent: right)
+ right.insert(value: value, parent: right)
  } else {
  right = BinarySearchTree(value: value)
  right?.parent = parent
@@ -108,7 +108,7 @@ extension BinarySearchTree {
 
  Performance: runs in O(h) time, where h is the height of the tree.
  */
- public func remove() -> BinarySearchTree? {
+ @discardableResult public func remove() -> BinarySearchTree? {
  let replacement: BinarySearchTree?
 
  if let left = left {
@@ -126,7 +126,7 @@ extension BinarySearchTree {
  replacement = nil
  }
 
- reconnectParentToNode(replacement)
+ reconnectParentTo(node: replacement)
 
  // The current node is no longer part of the tree, so clean it up.
  parent = nil
@@ -136,7 +136,7 @@ extension BinarySearchTree {
  return replacement
  }
 
- private func removeNodeWithTwoChildren(left: BinarySearchTree, _ right: BinarySearchTree) -> BinarySearchTree {
+ private func removeNodeWithTwoChildren(_ left: BinarySearchTree, _ right: BinarySearchTree) -> BinarySearchTree {
  // This node has two children. It must be replaced by the smallest
  // child that is larger than this node's value, which is the leftmost
  // descendent of the right child.
@@ -164,7 +164,7 @@ extension BinarySearchTree {
  return successor
  }
 
- private func reconnectParentToNode(node: BinarySearchTree?) {
+ private func reconnectParentTo(node: BinarySearchTree?) {
  if let parent = parent {
  if isLeftChild {
  parent.left = node
@@ -211,7 +211,7 @@ extension BinarySearchTree {
  */
 
  public func contains(value: T) -> Bool {
- return search(value) != nil
+ return search(value: value) != nil
  }
 
  /*
@@ -298,32 +298,32 @@ extension BinarySearchTree {
 // MARK: - Traversal
 
 extension BinarySearchTree {
- public func traverseInOrder(@noescape process: T -> Void) {
- left?.traverseInOrder(process)
+ public func traverseInOrder(process: (T) -> Void) {
+ left?.traverseInOrder(process: process)
  process(value)
- right?.traverseInOrder(process)
+ right?.traverseInOrder(process: process)
  }
 
- public func traversePreOrder(@noescape process: T -> Void) {
+ public func traversePreOrder(process: (T) -> Void) {
  process(value)
- left?.traversePreOrder(process)
- right?.traversePreOrder(process)
+ left?.traversePreOrder(process: process)
+ right?.traversePreOrder(process: process)
  }
 
- public func traversePostOrder(@noescape process: T -> Void) {
- left?.traversePostOrder(process)
- right?.traversePostOrder(process)
+ public func traversePostOrder(process: (T) -> Void) {
+ left?.traversePostOrder(process: process)
+ right?.traversePostOrder(process: process)
  process(value)
  }
 
  /*
  Performs an in-order traversal and collects the results in an array.
  */
- public func map(@noescape formula: T -> T) -> [T] {
+ public func map(formula: (T) -> T) -> [T] {
  var a = [T]()
- if let left = left { a += left.map(formula) }
+ if let left = left { a += left.map(formula: formula) }
  a.append(formula(value))
- if let right = right { a += right.map(formula) }
+ if let right = right { a += right.map(formula: formula) }
  return a
  }
 }
@@ -332,7 +332,7 @@ extension BinarySearchTree {
  Is this binary tree a valid binary search tree?
 */
 extension BinarySearchTree {
- public func isBST(minValue minValue: T, maxValue: T) -> Bool {
+ public func isBST(minValue: T, maxValue: T) -> Bool {
  if value < minValue || value > maxValue { return false }
  let leftBST = left?.isBST(minValue: minValue, maxValue: value) ?? true
  let rightBST = right?.isBST(minValue: value, maxValue: maxValue) ?? true