Merge pull request #334 from mattThousand/swift-3-heap-sort

Updating Heap Sort to Swift 3

.travis.yml

@@ -23,7 +23,7 @@ script:
 # - xcodebuild test -project ./Depth-First\ Search/Tests/Tests.xcodeproj -scheme Tests
 # - xcodebuild test -project ./Graph/Graph.xcodeproj -scheme GraphTests
 # - xcodebuild test -project ./Heap/Tests/Tests.xcodeproj -scheme Tests
-# - xcodebuild test -project ./Heap\ Sort/Tests/Tests.xcodeproj -scheme Tests
+- xcodebuild test -project ./Heap\ Sort/Tests/Tests.xcodeproj -scheme Tests
 - xcodebuild test -project ./Insertion\ Sort/Tests/Tests.xcodeproj -scheme Tests
 # - xcodebuild test -project ./K-Means/Tests/Tests.xcodeproj -scheme Tests
 # - xcodebuild test -project ./Linked\ List/Tests/Tests.xcodeproj -scheme Tests

Heap Sort/HeapSort.swift

@@ -1,8 +1,8 @@
 extension Heap {
   public mutating func sort() -> [T] {
-    for i in (elements.count - 1).stride(through: 1, by: -1) {
+    for i in stride(from: (elements.count - 1), through: 1, by: -1) {
       swap(&elements[0], &elements[i])
-      shiftDown(index: 0, heapSize: i)
+      shiftDown(0, heapSize: i)
     }
     return elements
   }
@@ -12,7 +12,7 @@ extension Heap {
   Sorts an array using a heap.
   Heapsort can be performed in-place, but it is not a stable sort.
 */
-public func heapsort<T>(a: [T], _ sort: (T, T) -> Bool) -> [T] {
+public func heapsort<T>(_ a: [T], _ sort: @escaping (T, T) -> Bool) -> [T] {
   let reverseOrder = { i1, i2 in sort(i2, i1) }
   var h = Heap(array: a, sort: reverseOrder)
   return h.sort()

Heap Sort/README.markdown

@@ -48,13 +48,13 @@ Here's how you can implement heap sort in Swift:
 
 ```swift
 extension Heap {
-  public mutating func sort() -> [T] {
-    for i in (elements.count - 1).stride(through: 1, by: -1) {
-      swap(&elements[0], &elements[i])
-      shiftDown(index: 0, heapSize: i)
-    }
+    public mutating func sort() -> [T] {
+        for i in stride(from: (elements.count - 1), through: 1, by: -1) {
+            swap(&elements[0], &elements[i])
+            shiftDown(0, heapSize: i)
+        }
     return elements
-  }
+    }
 }
 ```
 
@@ -70,10 +70,10 @@ Because we need a max-heap to sort from low-to-high, you need to give `Heap` the
 We can write a handy helper function for that:
 
 ```swift
-public func heapsort<T>(a: [T], _ sort: (T, T) -> Bool) -> [T] {
-  let reverseOrder = { i1, i2 in sort(i2, i1) }
-  var h = Heap(array: a, sort: reverseOrder)
-  return h.sort()
+public func heapsort<T>(_ a: [T], _ sort: @escaping (T, T) -> Bool) -> [T] {
+    let reverseOrder = { i1, i2 in sort(i2, i1) }
+    var h = Heap(array: a, sort: reverseOrder)
+    return h.sort()
 }
 ```
 

Heap Sort/Tests/Tests.xcodeproj/project.pbxproj

@@ -86,11 +86,12 @@
 			isa = PBXProject;
 			attributes = {
 				LastSwiftUpdateCheck = 0720;
-				LastUpgradeCheck = 0720;
+				LastUpgradeCheck = 0820;
 				ORGANIZATIONNAME = "Swift Algorithm Club";
 				TargetAttributes = {
 					7B2BBC7F1C779D720067B71D = {
 						CreatedOnToolsVersion = 7.2;
+						LastSwiftMigration = 0820;
 					};
 				};
 			};
@@ -149,8 +150,10 @@
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				CODE_SIGN_IDENTITY = "-";
@@ -193,8 +196,10 @@
 				CLANG_WARN_DIRECT_OBJC_ISA_USAGE = YES_ERROR;
 				CLANG_WARN_EMPTY_BODY = YES;
 				CLANG_WARN_ENUM_CONVERSION = YES;
+				CLANG_WARN_INFINITE_RECURSION = YES;
 				CLANG_WARN_INT_CONVERSION = YES;
 				CLANG_WARN_OBJC_ROOT_CLASS = YES_ERROR;
+				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				CODE_SIGN_IDENTITY = "-";
@@ -213,6 +218,7 @@
 				MACOSX_DEPLOYMENT_TARGET = 10.11;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = macosx;
+				SWIFT_OPTIMIZATION_LEVEL = "-Owholemodule";
 			};
 			name = Release;
 		};
@@ -224,6 +230,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = swift.algorithm.club.Tests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 3.0;
 			};
 			name = Debug;
 		};
@@ -235,6 +242,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = swift.algorithm.club.Tests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				SWIFT_VERSION = 3.0;
 			};
 			name = Release;
 		};

Heap Sort/Tests/Tests.xcodeproj/xcshareddata/xcschemes/Tests.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0720"
+   LastUpgradeVersion = "0820"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"

Heap/Heap.swift

@@ -46,7 +46,7 @@ public struct Heap<T> {
   fileprivate mutating func buildHeap(fromArray array: [T]) {
     elements = array
     for i in stride(from: (elements.count/2 - 1), through: 0, by: -1) {
-      shiftDown(index: i, heapSize: elements.count)
+      shiftDown(i, heapSize: elements.count)
     }
   }
 
@@ -98,7 +98,7 @@ public struct Heap<T> {
    */
   public mutating func insert(_ value: T) {
     elements.append(value)
-    shiftUp(index: elements.count - 1)
+    shiftUp(elements.count - 1)
   }
 
   public mutating func insert<S: Sequence>(_ sequence: S) where S.Iterator.Element == T {
@@ -116,7 +116,7 @@ public struct Heap<T> {
 
     assert(isOrderedBefore(value, elements[i]))
     elements[i] = value
-    shiftUp(index: i)
+    shiftUp(i)
   }
 
   /**
@@ -142,14 +142,14 @@ public struct Heap<T> {
    * Removes an arbitrary node from the heap. Performance: O(log n). You need
    * to know the node's index, which may actually take O(n) steps to find.
    */
-  public mutating func removeAt(index: Int) -> T? {
+  public mutating func removeAt(_ index: Int) -> T? {
     guard index < elements.count else { return nil }
 
     let size = elements.count - 1
     if index != size {
       swap(&elements[index], &elements[size])
-      shiftDown(index: index, heapSize: size)
-      shiftUp(index: index)
+      shiftDown(index, heapSize: size)
+      shiftUp(index)
     }
     return elements.removeLast()
   }
@@ -158,7 +158,7 @@ public struct Heap<T> {
    * Takes a child node and looks at its parents; if a parent is not larger
    * (max-heap) or not smaller (min-heap) than the child, we exchange them.
    */
-  mutating func shiftUp(index: Int) {
+  mutating func shiftUp(_ index: Int) {
     var childIndex = index
     let child = elements[childIndex]
     var parentIndex = self.parentIndex(ofIndex: childIndex)
@@ -173,14 +173,14 @@ public struct Heap<T> {
   }
 
   mutating func shiftDown() {
-    shiftDown(index: 0, heapSize: elements.count)
+    shiftDown(0, heapSize: elements.count)
   }
 
   /**
    * Looks at a parent node and makes sure it is still larger (max-heap) or
    * smaller (min-heap) than its childeren.
    */
-  mutating func shiftDown(index: Int, heapSize: Int) {
+  mutating func shiftDown(_ index: Int, heapSize: Int) {
     var parentIndex = index
 
     while true {