[Swift 4] Update Huffman Coding

Author: remlostime

Huffman Coding/Huffman.playground/Contents.swift

@@ -1,5 +1,10 @@
 //: Playground - noun: a place where people can play
 
+// last checked with Xcode 9.0b4
+#if swift(>=4.0)
+print("Hello, Swift 4!")
+#endif
+
 import Foundation
 
 let s1 = "so much words wow many compression"

Huffman Coding/Huffman.playground/Sources/Heap.swift

@@ -143,7 +143,7 @@ public struct Heap<T> {
   public mutating func removeAtIndex(i: Int) -> T? {
     let size = elements.count - 1
     if i != size {
-      swap(&elements[i], &elements[size])
+      elements.swapAt(i, size)
       shiftDown(index: i, heapSize: size)
       shiftUp(index: i)
     }
@@ -196,7 +196,7 @@ public struct Heap<T> {
       }
       if first == parentIndex { return }
 
-      swap(&elements[parentIndex], &elements[first])
+      elements.swapAt(parentIndex, first)
       parentIndex = first
     }
   }

Huffman Coding/Huffman.playground/timeline.xctimeline

@@ -3,12 +3,12 @@
    version = "3.0">
    <TimelineItems>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "file:///Users/peter/Programming/iOS/Workspace/swift-algorithm-club/Huffman%20Coding/Huffman.playground#CharacterRangeLen=19&amp;CharacterRangeLoc=678&amp;EndingLineNumber=21&amp;StartingLineNumber=21&amp;Timestamp=505135214.929897"
+         documentLocation = "file:///Users/kachen/src/swift-algorithm-club/Huffman%20Coding/Huffman.playground#CharacterRangeLen=0&amp;CharacterRangeLoc=752&amp;EndingColumnNumber=0&amp;EndingLineNumber=28&amp;StartingColumnNumber=0&amp;StartingLineNumber=28&amp;Timestamp=523212028.643394"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>
       <LoggerValueHistoryTimelineItem
-         documentLocation = "#CharacterRangeLen=14&amp;CharacterRangeLoc=350&amp;EndingColumnNumber=21&amp;EndingLineNumber=12&amp;StartingColumnNumber=7&amp;StartingLineNumber=12&amp;Timestamp=505138287.94525"
+         documentLocation = "file:///Users/kachen/src/swift-algorithm-club/Huffman%20Coding/Huffman.playground#CharacterRangeLen=14&amp;CharacterRangeLoc=433&amp;EndingColumnNumber=36&amp;EndingLineNumber=17&amp;StartingColumnNumber=22&amp;StartingLineNumber=17&amp;Timestamp=523212028.643973"
          selectedRepresentationIndex = "0"
          shouldTrackSuperviewWidth = "NO">
       </LoggerValueHistoryTimelineItem>