Merge pull request kodecocodes#353 from taiheng/feature/swift3-radixsort

Convert RadixSort to swift3 syntax

Author: vincentngo

.travis.yml

@@ -33,6 +33,7 @@ script:
 # - xcodebuild test -project ./Priority\ Queue/Tests/Tests.xcodeproj -scheme Tests
 - xcodebuild test -project ./Queue/Tests/Tests.xcodeproj -scheme Tests
 # - xcodebuild test -project ./Quicksort/Tests/Tests.xcodeproj -scheme Tests
+- xcodebuild test -project ./Radix\ Sort/Tests/Tests.xcodeproj -scheme Tests
 - xcodebuild test -project ./Rootish\ Array\ Stack/Tests/Tests.xcodeproj -scheme Tests
 # - xcodebuild test -project ./Run-Length\ Encoding/Tests/Tests.xcodeproj -scheme Tests
 # - xcodebuild test -project ./Select\ Minimum\ Maximum/Tests/Tests.xcodeproj -scheme Tests

Radix Sort/RadixSort.playground/Contents.swift

@@ -0,0 +1,16 @@
+//: Playground - noun: a place where people can play
+
+import Cocoa
+
+// Test Radix Sort with small array of ten values
+var array: [Int] = [19, 4242, 2, 9, 912, 101, 55, 67, 89, 32]
+radixSort(&array)
+
+// Test Radix Sort with large array of 1000 random values
+var bigArray = [Int](repeating: 0, count: 1000)
+var i = 0
+while i < 1000 {
+  bigArray[i] = Int(arc4random_uniform(1000) + 1)
+  i += 1
+}
+radixSort(&bigArray)

Radix Sort/RadixSort.playground/Sources/radixSort.swift

@@ -0,0 +1,46 @@
+/*
+ 
+ Sorting Algorithm that sorts an input array of integers digit by digit.
+ 
+ */
+import Foundation
+
+// NOTE: This implementation does not handle negative numbers
+public func radixSort(_ array: inout [Int] ) {
+  let radix = 10  //Here we define our radix to be 10
+  var done = false
+  var index: Int
+  var digit = 1  //Which digit are we on?
+  
+  
+  while !done {  //While our  sorting is not completed
+    done = true  //Assume it is done for now
+    
+    var buckets: [[Int]] = []  //Our sorting subroutine is bucket sort, so let us predefine our buckets
+    
+    for _ in 1...radix {
+      buckets.append([])
+    }
+    
+    
+    for number in array {
+      index = number / digit  //Which bucket will we access?
+      buckets[index % radix].append(number)
+      if done && index > 0 {  //If we arent done, continue to finish, otherwise we are done
+        done = false
+      }
+    }
+    
+    var i = 0
+    
+    for j in 0..<radix {
+      let bucket = buckets[j]
+      for number in bucket {
+        array[i] = number
+        i += 1
+      }
+    }
+    
+    digit *= radix  //Move to the next digit
+  }
+}

Radix Sort/RadixSort.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='macos'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

Radix Sort/RadixSort.playground/playground.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,22 @@
+<?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>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>BNDL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+</dict>
+</plist>

Radix Sort/Tests/Info.plist

@@ -0,0 +1,18 @@
+//
+//  RadixSortTests.swift
+//  Tests
+//
+//  Created by theng on 2017-01-10.
+//  Copyright © 2017 Swift Algorithm Club. All rights reserved.
+//
+
+import XCTest
+
+class RadixSortTests: XCTestCase {
+  func testCombSort() {
+    let expectedSequence: [Int] = [2, 9, 19, 32, 55, 67, 89, 101, 912, 4242]
+    var sequence = [19, 4242, 2, 9, 912, 101, 55, 67, 89, 32]
+    radixSort(&sequence)
+    XCTAssertEqual(sequence, expectedSequence)
+  }
+}