Merge pull request kodecocodes#360 from boqian2000/master

Simplify the insert method

Author: kelvinlauKL

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

@@ -23,7 +23,7 @@ public class BinarySearchTree<T: Comparable> {
  precondition(array.count > 0)
  self.init(value: array.first!)
  for v in array.dropFirst() { 
- insert(value: v, parent: self)
+ insert(value: v)
  }
  }
 
@@ -74,23 +74,19 @@ extension BinarySearchTree {
  Performance: runs in O(h) time, where h is the height of the tree.
  */
  public func insert(value: T) {
- insert(value: value, parent: self)
- }
-
- fileprivate func insert(value: T, parent: BinarySearchTree) {
  if value < self.value {
  if let left = left {
- left.insert(value: value, parent: left)
+ left.insert(value: value)
  } else {
  left = BinarySearchTree(value: value)
- left?.parent = parent
+ left?.parent = self
  }
  } else {
  if let right = right {
- right.insert(value: value, parent: right)
+ right.insert(value: value)
  } else {
  right = BinarySearchTree(value: value)
- right?.parent = parent
+ right?.parent = self
  }
  }
  }