Add swift implementation of Doomsday

zskamljic · zskamljic · commit 7ac44baef36d · 2017-10-15T21:21:55.000+02:00
diff --git a/Doomsday/Swift/Doomsday.swift b/Doomsday/Swift/Doomsday.swift
@@ -0,0 +1,27 @@
+func dow(year: Int, month: Int, day: Int) -> Int {
+    var year = year
+    let t = [0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4]
+    year -= month < 3 ? 1 : 0
+    return (year + year / 4 - year / 100 + year / 400 + t[month - 1] + day) % 7
+}
+
+func dowS(year: Int, month: Int, day: Int) -> String {
+    switch (dow(year: year, month: month, day: day)) {
+        case 0: return "Sunday"
+        case 1: return "Monday"
+        case 2: return "Tuesday"
+        case 3: return "Wednesday"
+        case 4: return "Thursday"
+        case 5: return "Friday"
+        case 6: return "Saturday"
+        default: return "Invalid ordinal"
+    }
+}
+
+print("\(dow(year: 1886, month: 5, day: 1)): \(dowS(year: 1886, month: 5, day: 1))")
+print("\(dow(year: 1948, month: 12, day: 10)): \(dowS(year: 1948, month: 12, day: 10))")
+print("\(dow(year: 2001, month: 1, day: 15)): \(dowS(year: 2001, month: 1, day: 15))")
+print("\(dow(year: 2017, month: 10, day: 10)): \(dowS(year: 2017, month: 10, day: 10))")
+print("\(dow(year: 2018, month: 1, day: 1)): \(dowS(year: 2018, month: 1, day: 1))")
+print("\(dow(year: 2018, month: 2, day: 16)): \(dowS(year: 2018, month: 2, day: 16))")
+print("\(dow(year: 2018, month: 5, day: 17)): \(dowS(year: 2018, month: 5, day: 17))")
