tiny changes to comments

Author: davecom

Classic Computer Science Problems in Swift.playground/Pages/Chapter 1.xcplaygroundpage/Contents.swift

@@ -167,9 +167,9 @@ func calculatePi(nTerms: UInt) -> Double {
     var operation: Double = -1
     var pi: Double = 0
     for _ in 0..<nTerms {
-        pi = pi + operation * (numerator / denominator)
+        pi += operation * (numerator / denominator)
         denominator += 2
-        operation = operation * -1
+        operation *= -1
     }
     return abs(pi)
 }
@@ -179,7 +179,7 @@ calculatePi(nTerms: 1000)
 
 /// The Towers of Hanoi
 
-/// Implements a stack - helper class that uses an array internally.
+/// Implements a stack - LIFO helper class that uses an array internally.
 public class Stack<T>: CustomStringConvertible {
     private var container: [T] = [T]()
     public func push(_ thing: T) { container.append(thing) }

Classic Computer Science Problems in Swift.playground/Pages/Chapter 2.xcplaygroundpage/Contents.swift

@@ -102,7 +102,7 @@ for _ in 0..<1000 {
 }
 let elapsedTime2 = CFAbsoluteTimeGetCurrent() - startTime2*/
 
-//generic versions for dictionary
+/// Generic Versions
 
 func linearContains<T: Equatable>(_ array: [T], item: T) -> Bool {
     for element in array where item == element {
@@ -111,10 +111,6 @@ func linearContains<T: Equatable>(_ array: [T], item: T) -> Bool {
     return false
 }
 
-//linearContains(gene, item: ac1)
-
-gene.sort(by: <)
-
 func binaryContains<T: Comparable>(_ array: [T], item: T) -> Bool {
     var low = 0
     var high = array.count - 1