Shell Sort

Author: mitghi

Shell Sort/shellsort.swift

@@ -21,9 +21,7 @@
 // SOFTWARE.
 
 func insertionSort(inout list: [Int],start: Int, gap: Int) {
-    var i: Int
-    
-    for i = start + gap; i < list.count; i += gap {
+    for i in (start + gap).stride(to: list.count, by: gap){
         let currentValue = list[i]
         var pos = i
         while pos >= gap && list[pos - gap] > currentValue {