binarytrees benchmark for swift (#369)

Author: acefsm

bench/algorithm/binarytrees/1.swift

@@ -0,0 +1,48 @@
+import Foundation
+
+let minDepth = UInt32(4)
+let maxDepth = CommandLine.argc > 1 ? max(UInt32(CommandLine.arguments[1]) ?? 0, minDepth + 2) : 10
+let stretchDepth = maxDepth + 1
+let check = Tree(depth: stretchDepth).check
+print("stretch tree of depth \(stretchDepth)\t check: \(check)")
+
+let longLivingTree = Tree(depth: maxDepth)
+
+for halfDepth in (minDepth / 2)..<(maxDepth / 2 + 1) {
+    let depth = halfDepth * 2
+    let iterations = UInt32(1 << (maxDepth - depth + minDepth))
+    var chk: UInt32 = 0
+    for _ in 1...iterations {
+        chk += Tree(depth: depth).check
+    }
+    print("\(iterations)\t trees of depth \(depth)\t check: \(chk)")
+}
+
+print("long lived tree of depth \(maxDepth)\t check: \(longLivingTree.check)")
+
+indirect enum Tree {
+    case Empty
+    case Node(left: Tree, right: Tree)
+    
+    init(depth: UInt32) {
+        if depth > 0 {
+            self = .Node(left: Tree(depth: depth - 1), right: Tree(depth: depth - 1))
+        } else {
+            self = .Node(left: .Empty, right: .Empty)
+        }
+    }
+    
+    var check: UInt32 {
+        switch self {
+        case .Node(let left, let right):
+            switch (left, right) {
+            case (.Empty, .Empty):
+                return 1
+            default:
+                return 1 + left.check + right.check
+            }
+        case .Empty:
+            return 1
+        }
+    }
+}

bench/bench_swift.yaml

@@ -3,6 +3,9 @@ problems:
   - name: helloworld
     source:
       - 1.swift
+  - name: binarytrees
+    source:
+      - 1.swift      
   - name: nbody
     source:
       - 7.swift