Merging master

Author: kelvinlauKL

.github/CONTRIBUTING.md

@@ -6,7 +6,7 @@ Want to help out with the Swift Algorithm Club? Great! While we don't have stric
 
 Our repo is all about learning. The `README` file is the cake, and the sample code is the cherry on top. A good contribution has succinct explanations supported by diagrams. Code is best introduced in chunks, weaved into the explanations where relevant. 
 
-> When choosing between brievity and performance, err to the side of brievity as long as the time complexity of the particular implementation is the same. You can make a note afterwards suggesting a more performant way of doing things. 
+> When choosing between brevity and performance, err to the side of brevity as long as the time complexity of the particular implementation is the same. You can make a note afterwards suggesting a more performant way of doing things. 
 
 **API Design Guidelines**
 
@@ -22,7 +22,7 @@ We follow the following Swift [style guide](https://github.com/raywenderlich/swi
 
 Unit tests. Fixes for typos. No contribution is too small. :-)
 
-The repository has over 100 different data structures and algorithms. We're always interested in improvements to existing implementations and better explanations. Suggestions for making the code more Swift-like or to make it fit better with the standard library is most welcomed. 
+The repository has over 100 different data structures and algorithms. We're always interested in improvements to existing implementations and better explanations. Suggestions for making the code more Swift-like or to make it fit better with the standard library are most welcome.
 
 ### New Contributions
 

.travis.yml

@@ -1,3 +1,7 @@
+// last checked with Xcode 10.1
+#if swift(>=4.2)
+print("Hello, Swift 4.2!")
+#endif
 
 extension Collection where Element: Equatable {
 

3Sum and 4Sum/3Sum.playground/Contents.swift

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

Binary Search/BinarySearch.playground/playground.xcworkspace/contents.xcworkspacedata renamed to 3Sum and 4Sum/3Sum.playground/playground.xcworkspace/contents.xcworkspacedata

@@ -1,3 +1,8 @@
+// last checked with Xcode 10.1
+#if swift(>=4.2)
+print("Hello, Swift 4.2!")
+#endif
+
 extension Collection where Element: Equatable {
 
   /// In a sorted collection, replaces the given index with a successor mapping to a unique element.

3Sum and 4Sum/3Sum.playground/playground.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

3Sum and 4Sum/4Sum.playground/Contents.swift

@@ -1,9 +1,5 @@
 //: Playground - noun: a place where people can play
 
-// last checked with Xcode 9.0b4
-#if swift(>=4.0)
-print("Hello, Swift 4!")
-#endif
 
 let tree = AVLTree<Int, String>()
 

Fizz Buzz/FizzBuzz.playground/playground.xcworkspace/contents.xcworkspacedata renamed to 3Sum and 4Sum/4Sum.playground/playground.xcworkspace/contents.xcworkspacedata

@@ -88,4 +88,4 @@ The interesting bits are in the `balance()` method which is called after inserti
 
 AVL tree was the first self-balancing binary tree. These days, the [red-black tree](../Red-Black%20Tree/) seems to be more popular.
 
-*Written for Swift Algorithm Club by Mike Taghavi and Matthijs Hollemans*
+*Written for Swift Algorithm Club by [Mike Taghavi](https://github.com/mitghi) and [Matthijs Hollemans](https://github.com/hollance)*