diff --git a/Count Occurrences/README.markdown b/Count Occurrences/README.markdown
index 8e935ea58..95f020e90 100644
--- a/Count Occurrences/README.markdown	
+++ b/Count Occurrences/README.markdown	
@@ -28,7 +28,7 @@ func countOccurrences<T: Comparable>(of key: T, in array: [T]) -> Int {
     var high = array.count
     while low < high {
       let midIndex = low + (high - low)/2
-      if a[midIndex] < key {
+      if array[midIndex] < key {
         low = midIndex + 1
       } else {
         high = midIndex
@@ -42,7 +42,7 @@ func countOccurrences<T: Comparable>(of key: T, in array: [T]) -> Int {
     var high = array.count
     while low < high {
       let midIndex = low + (high - low)/2
-      if a[midIndex] > key {
+      if array[midIndex] > key {
         high = midIndex
       } else {
         low = midIndex + 1
diff --git a/Kth Largest Element/README.markdown b/Kth Largest Element/README.markdown
index b23d22b74..7e60a8d4a 100644
--- a/Kth Largest Element/README.markdown	
+++ b/Kth Largest Element/README.markdown	
@@ -88,7 +88,7 @@ public func randomizedSelect<T: Comparable>(_ array: [T], order k: Int) -> T {
   var a = array
 
   func randomPivot<T: Comparable>(_ a: inout [T], _ low: Int, _ high: Int) -> T {
-    let pivotIndex = random(min: low, max: high)
+    let pivotIndex = Int.random(in: low...high)
     a.swapAt(pivotIndex, high)
     return a[high]
   }
diff --git a/Selection Sampling/README.markdown b/Selection Sampling/README.markdown
index 741f592f4..11465b90e 100644
--- a/Selection Sampling/README.markdown	
+++ b/Selection Sampling/README.markdown	
@@ -7,6 +7,12 @@ Let's say you have a deck of 52 playing cards and you need to draw 10 cards at r
 Here's a very fast version:
 
 ```swift
+public func random(min: Int, max: Int) -> Int {
+  assert(min < max)
+  return min + Int(arc4random_uniform(UInt32(max - min + 1)))
+}
+
+
 func select<T>(from a: [T], count k: Int) -> [T] {
   var a = a
   for i in 0..<k {
diff --git a/Selection Sampling/SelectionSampling.playground/Contents.swift b/Selection Sampling/SelectionSampling.playground/Contents.swift
index 7443db67c..81989b8a3 100644
--- a/Selection Sampling/SelectionSampling.playground/Contents.swift	
+++ b/Selection Sampling/SelectionSampling.playground/Contents.swift	
@@ -19,7 +19,7 @@ func select<T>(from a: [T], count k: Int) -> [T] {
   for i in 0..<k {
     let r = random(min: i, max: a.count - 1)
     if i != r {
-      swap(&a[i], &a[r])
+        a.swapAt(i, r)
     }
   }
   return Array(a[0..<k])