Data commit

Task/Vampire-number/Swift/vampire-number.swift

@@ -0,0 +1,54 @@
+import Foundation
+
+func vampire<T>(n: T) -> [(T, T)] where T: BinaryInteger, T.Stride: SignedInteger {
+  let strN = String(n).sorted()
+  let fangLength = strN.count / 2
+  let start = T(pow(10, Double(fangLength - 1)))
+  let end = T(Double(n).squareRoot())
+
+  var fangs = [(T, T)]()
+
+  for i in start...end where n % i == 0 {
+    let quot = n / i
+
+    guard i % 10 != 0 || quot % 10 != 0 else {
+      continue
+    }
+
+    if "\(i)\(quot)".sorted() == strN {
+      fangs.append((i, quot))
+    }
+  }
+
+  return fangs
+}
+
+var count = 0
+var i = 1.0
+
+while count < 25 {
+  let start = Int(pow(10, i))
+  let end = start * 10
+
+  for num in start...end {
+    let fangs = vampire(n: num)
+
+    guard !fangs.isEmpty else { continue }
+
+    count += 1
+
+    print("\(num) is a vampire number with fangs: \(fangs)")
+
+    guard count != 25 else { break }
+  }
+
+  i += 2
+}
+
+for (vamp, fangs) in [16758243290880, 24959017348650, 14593825548650].lazy.map({ ($0, vampire(n: $0)) }) {
+  if fangs.isEmpty {
+    print("\(vamp) is not a vampire number")
+  } else {
+    print("\(vamp) is a vampire number with fangs: \(fangs)")
+  }
+}