Data commit

Task/Fusc-sequence/Swift/fusc-sequence.swift

@@ -0,0 +1,41 @@
+struct FuscSeq: Sequence, IteratorProtocol {
+  private var arr = [0, 1]
+  private var i = 0
+
+  mutating func next() -> Int? {
+    defer {
+      i += 1
+    }
+
+    guard i > 1 else {
+      return arr[i]
+    }
+
+    switch i & 1 {
+    case 0:
+      arr.append(arr[i / 2])
+    case 1:
+      arr.append(arr[(i - 1) / 2] + arr[(i + 1) / 2])
+    case _:
+      fatalError()
+    }
+
+    return arr.last!
+  }
+}
+
+let first = FuscSeq().prefix(61)
+
+print("First 61: \(Array(first))")
+
+var max = -1
+
+for (i, n) in FuscSeq().prefix(20_000_000).enumerated() {
+  let f = String(n).count
+
+  if f > max {
+    max = f
+
+    print("New max: \(i): \(n)")
+  }
+}