initial solution

longest-run-linux/Source/main.swift

@@ -0,0 +1,49 @@
+/* 
+The challenge here is to implement the longestRun function so that the
+longest run of the same continuous character will be selected from a String.
+This excercise lends itself to TDD and we have provided a few basic tests below.
+*/
+
+// import Cocoa
+
+func longestRun(whole: String) -> String {
+    var currentMaxLen = 0
+    var currentMaxChar:Character = " "
+    var currentLen = 0
+    var currentChar:Character = " "
+    for char in whole.characters {
+        if char != currentChar {
+            currentChar = char
+            currentLen = 1
+        }
+        else {
+            currentLen++
+        }
+
+        if currentLen > currentMaxLen {
+            currentMaxLen = currentLen
+            currentMaxChar = currentChar
+        }
+
+    }
+
+    var subStr = ""
+    for _ in 1...currentMaxLen {
+        subStr.append(currentMaxChar)
+    }
+
+    return subStr
+}
+
+let result = longestRun("zzzz")
+
+// identity test
+var zzzz = "zzzz"
+assert(zzzz == longestRun(zzzz), "\(zzzz) should be the longest run of chars")
+
+print("hello linux \(result)")
+
+// book
+// var book = "book"
+// assert("oo" == longestRun(book), "longest run in \(book) is 'oo'")
+