Add examples on Swift 3.0.2 (#11)

* 01_binary_search Swift 3.0.2

* 01_binary_search Swift 3.0.2

* add Chapter 2 - 01_selection_sort Swift 3.0.2 example

* 01_binary_search cosmetic note updates Swift 3.0.2

* 03_recursion Swift 3.0.2 examples

* 04_quicksort Swift 3.0.2 examples

* fix typo on quicksort example. Swift 3.0.2

* add  05_hash_tables examples on Swift 3.0.2

* add 01_breadth-first_search Swift 3.0.2 example

* 01_breadth-first_search fixing typo Swift 3.0.2

* add 01_dijkstras_algorithm on Swift 3.0.2

* add 08_greedy_algorithms Swift 3.0.2 example

* 01_longest_common_subsequence Swift 3.0.2 example

05_hash_tables/swift/01_price_of_groceries.swift

@@ -0,0 +1,18 @@
+import Foundation
+
+var book = [String: Double]()
+// an apple costs 67 cents
+book["apple"] = 0.67
+//# milk costs $1.49
+book["milk"] = 1.49
+book["avacado"] = 1.49
+print(book) // => ["avacado": 1.49, "apple": 0.67000000000000004, "milk": 1.49]
+
+// Qustion: Why is "apple" is 0.67000000000000004 intsted of 0.67?
+// Answer: Double cannot store the value 0.67 exactly. Swift uses (like many other languages) binary floating point numbers according to the IEEE 754 standard.
+// This topic is not related with Algorithms, but you can play with .description and .debugDescription for making workarrounds 
+print(book["apple"]?.description ?? "Not exist") // => 0.67
+print(book["apple"]?.debugDescription ?? "Not exist") // => 0.67000000000000004
+
+
+

05_hash_tables/swift/02_check_voter.swift

@@ -0,0 +1,18 @@
+import Foundation
+
+var voter = [String : Bool]()
+
+func checkVoter(_ name : String) {
+    if voter[name] != nil {
+        print("kick them out!")
+    } else {
+        voter[name] = true
+        print("let them vote!")
+    }
+}
+
+checkVoter("tom")
+checkVoter("mike")
+checkVoter("mike")
+
+