Data commit

Task/Perfect-shuffle/Dyalect/perfect-shuffle.dyalect

@@ -0,0 +1,46 @@
+func shuffle(arr) {
+    if arr.Length() % 2 != 0 {
+        throw @InvalidValue(arr.Length())
+    }
+    var half = arr.Length() / 2
+    var result = Array.Empty(arr.Length())
+    var (t, l, r) = (0, 0, half)
+
+    while l < half {
+        result[t] = arr[l]
+        result[t+1] = arr[r]
+        l += 1
+        r += 1
+        t += 2
+    }
+    result
+}
+
+func arrayEqual(xs, ys) {
+    if xs.Length() != ys.Length() {
+        return false
+    }
+    for i in xs.Indices() {
+        if xs[i] != ys[i] {
+            return false
+        }
+    }
+    return true
+}
+
+func shuffleThrough(original) {
+    var copy = original.Clone()
+
+    while true {
+        copy = shuffle(copy)
+        yield copy
+        if arrayEqual(original, copy) {
+            break
+        }
+    }
+}
+
+for input in yields { 8, 24, 52, 100, 1020, 1024, 10000} {
+    var numbers = [1..input]
+    print("\(input) cards: \(shuffleThrough(numbers).Length())")
+}