Update Count Occurrences to Swift 3

Count Occurrences/CountOccurrences.playground/Contents.swift

@@ -1,6 +1,6 @@
 //: Playground - noun: a place where people can play
 
-func countOccurrencesOfKey(key: Int, inArray a: [Int]) -> Int {
+func countOccurrencesOfKey(_ key: Int, inArray a: [Int]) -> Int {
   func leftBoundary() -> Int {
     var low = 0
     var high = a.count
@@ -53,7 +53,7 @@ func createArray() -> [Int] {
       }
     }
   }
-  return a.sort(<)
+  return a.sorted()
 }
 
 for _ in 0..<10 {

Count Occurrences/CountOccurrences.swift

@@ -2,7 +2,7 @@
   Counts the number of times a value appears in an array in O(lg n) time.
   The array must be sorted from low to high.
 */
-func countOccurrencesOfKey(key: Int, inArray a: [Int]) -> Int {
+func countOccurrencesOfKey(_ key: Int, inArray a: [Int]) -> Int {
   func leftBoundary() -> Int {
     var low = 0
     var high = a.count

Count Occurrences/README.markdown

@@ -22,7 +22,7 @@ The trick is to use two binary searches, one to find where the `3`s start (the l
 In code this looks as follows:
 
 ```swift
-func countOccurrencesOfKey(key: Int, inArray a: [Int]) -> Int {
+func countOccurrencesOfKey(_ key: Int, inArray a: [Int]) -> Int {
   func leftBoundary() -> Int {
     var low = 0
     var high = a.count