Add 2015

2015/Day4.playground/Contents.swift

@@ -0,0 +1,24 @@
+import CryptoKit
+import Foundation
+
+func md5(_ string: String) -> String {
+    let digest = Insecure.MD5.hash(data: Data(string.utf8))
+    digest.withUnsafeBytes { ptr in
+        ptr[0] + ptr[1]
+    }
+    digest.pref
+    return digest.reduce("") {
+        $0 + String($1, radix: 16)
+    }
+}
+
+let key = "abcdef"
+
+var iterator = (0...).lazy.map { ($0, md5("\(key)\($0)")) }
+.filter { $0.1.hasPrefix("00000" ) }
+.makeIterator()
+
+iterator.next()
+
+
+

2015/Day4.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='ios' buildActiveScheme='true' importAppTypes='true'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

2015/Day4.playground/playground.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:">
+   </FileRef>
+</Workspace>