Merge pull request kodecocodes#745 from JulioBBL/select-sort

Select sort improvements

Author: richard-ash

Selection Sort/SelectionSort.playground/Contents.swift

@@ -6,5 +6,6 @@ print("Hello, Swift 4!")
 #endif
 
 let list = [ 10, -1, 3, 9, 2, 27, 8, 5, 1, 3, 0, 26 ]
+selectionSort(list)
 selectionSort(list, <)
 selectionSort(list, >)

Selection Sort/SelectionSort.playground/Sources/SelectionSort.swift

@@ -1,21 +1,35 @@
-public func selectionSort<T: Comparable>(_ array: [T], _ isOrderedBefore: (T, T) -> Bool) -> [T] {
-  guard array.count > 1 else { return array }
-
-  var a = array
-  for x in 0 ..< a.count - 1 {
-
-    // Find the lowest value in the rest of the array.
-    var lowest = x
-    for y in x + 1 ..< a.count {
-      if isOrderedBefore(a[y], a[lowest]) {
-        lowest = y
-      }
-    }
+/// Performs the Selection sort algorithm on a array
+///
+/// - Parameter array: array of elements that conform to the Comparable protocol
+/// - Returns: an array in ascending order
+public func selectionSort<T: Comparable>(_ array: [T]) -> [T] {
+  return insertionSort(array, <)
+}
 
-    // Swap the lowest value with the current array index.
-    if x != lowest {
-      a.swapAt(x, lowest)
+/// Performs the Selection sort algorithm on a array using the provided comparisson method
+///
+/// - Parameters:
+///   - array: array of elements that conform to the Comparable protocol
+///   - isLowerThan: returns true if the two provided elements are in the correct order
+/// - Returns: a sorted array
+public func selectionSort<T>(_ array: [T], _ isLowerThan: (T, T) -> Bool) -> [T] {
+    guard array.count > 1 else { return array }
+    
+    var a = array
+    for x in 0 ..< a.count - 1 {
+        
+        // Find the lowest value in the rest of the array.
+        var lowest = x
+        for y in x + 1 ..< a.count {
+            if isLowerThan(a[y], a[lowest]) {
+                lowest = y
+            }
+        }
+        
+        // Swap the lowest value with the current array index.
+        if x != lowest {
+            a.swapAt(x, lowest)
+        }
     }
-  }
-  return a
+    return a
 }

Selection Sort/SelectionSort.playground/playground.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>