Data commit

Task/Number-names/Swift/number-names.swift

@@ -0,0 +1,134 @@
+extension Int {
+  private static let bigNames = [
+    1_000: "thousand",
+    1_000_000: "million",
+    1_000_000_000: "billion",
+    1_000_000_000_000: "trillion",
+    1_000_000_000_000_000: "quadrillion",
+    1_000_000_000_000_000_000: "quintillion"
+  ]
+
+  private static let names = [
+    1: "one",
+    2: "two",
+    3: "three",
+    4: "four",
+    5: "five",
+    6: "six",
+    7: "seven",
+    8: "eight",
+    9: "nine",
+    10: "ten",
+    11: "eleven",
+    12: "twelve",
+    13: "thirteen",
+    14: "fourteen",
+    15: "fifteen",
+    16: "sixteen",
+    17: "seventeen",
+    18: "eighteen",
+    19: "nineteen",
+    20: "twenty",
+    30: "thirty",
+    40: "forty",
+    50: "fifty",
+    60: "sixty",
+    70: "seventy",
+    80: "eighty",
+    90: "ninety"
+  ]
+
+  public var numberName: String {
+    guard self != 0 else {
+      return "zero"
+    }
+
+    let neg = self < 0
+    let maxNeg = self == Int.min
+    var nn: Int
+
+    if maxNeg {
+      nn = -(self + 1)
+    } else if neg {
+      nn = -self
+    } else {
+      nn = self
+    }
+
+    var digits3 = [Int](repeating: 0, count: 7)
+
+    for i in 0..<7 {
+      digits3[i] = (nn % 1000)
+      nn /= 1000
+    }
+
+    func threeDigitsToText(n: Int) -> String {
+      guard n != 0 else {
+        return ""
+      }
+
+      var ret = ""
+
+      let hundreds = n / 100
+      let remainder = n % 100
+
+      if hundreds > 0 {
+        ret += "\(Int.names[hundreds]!) hundred"
+
+        if remainder > 0 {
+          ret += " "
+        }
+      }
+
+      if remainder > 0 {
+        let tens = remainder / 10
+        let units = remainder % 10
+
+        if tens > 1 {
+          ret += Int.names[tens * 10]!
+
+          if units > 0 {
+            ret += "-\(Int.names[units]!)"
+          }
+        } else {
+          ret += Int.names[remainder]!
+        }
+      }
+
+      return ret
+    }
+
+    let strings = (0..<7).map({ threeDigitsToText(n: digits3[$0]) })
+    var name = strings[0]
+    var big = 1000
+
+    for i in 1...6 {
+      if digits3[i] > 0 {
+        var name2 = "\(strings[i]) \(Int.bigNames[big]!)"
+
+        if name.count > 0 {
+          name2 += ", "
+        }
+
+        name = name2 + name
+      }
+
+      big &*= 1000
+    }
+
+    if maxNeg {
+      name = String(name.dropLast(5) + "eight")
+    }
+
+    return neg ? "minus \(name)" : name
+  }
+}
+
+let nums = [
+  0, 1, 7, 10, 18, 22, 67, 99, 100, 105, 999, -1056, 1000005000,
+  2074000000, 1234000000745003, Int.min
+]
+
+for number in nums {
+  print("\(number) => \(number.numberName)")
+}