Merge pull request kodecocodes#828 from RandyTheDev/min-edit-distance-4.2

[Swift 4.2] Updated Minimum Edit Distance Playground for Swift 4.2

Author: richard-ash

Minimum Edit Distance/MinimumEditDistance.playground/Contents.swift

@@ -1,15 +1,11 @@
 
 // Minimum Edit Distance
-// last checked with Xcode 9.0b4
-#if swift(>=4.0)
-print("Hello, Swift 4!")
-#endif
 
 extension String {
 
     public func minimumEditDistance(other: String) -> Int {
-        let m = self.characters.count
-        let n = other.characters.count
+        let m = self.count
+        let n = other.count
         var matrix = [[Int]](repeating: [Int](repeating: 0, count: n + 1), count: m + 1)
 
         // initialize matrix
@@ -24,8 +20,8 @@ extension String {
         }
 
         // compute Levenshtein distance
-        for (i, selfChar) in self.characters.enumerated() {
-            for (j, otherChar) in other.characters.enumerated() {
+        for (i, selfChar) in self.enumerated() {
+            for (j, otherChar) in other.enumerated() {
                 if otherChar == selfChar {
                     // substitution of equal symbols with cost 0
                     matrix[i + 1][j + 1] = matrix[i][j]

Minimum Edit Distance/README.markdown

@@ -37,8 +37,8 @@ Then in each cell the minimum of the cost of insertion, deletion, or substitutio
 
 ```swift
 // compute Levenshtein distance
-for (i, selfChar) in self.characters.enumerated() {
-    for (j, otherChar) in other.characters.enumerated() {
+for (i, selfChar) in self.enumerated() {
+    for (j, otherChar) in other.enumerated() {
         if otherChar == selfChar {
             // substitution of equal symbols with cost 0
             matrix[i + 1][j + 1] = matrix[i][j]