Initial data commit

Task/Additive-primes/Swift/additive-primes.swift

@@ -0,0 +1,46 @@
+import Foundation
+
+func isPrime(_ n: Int) -> Bool {
+    if n < 2 {
+        return false
+    }
+    if n % 2 == 0 {
+        return n == 2
+    }
+    if n % 3 == 0 {
+        return n == 3
+    }
+    var p = 5
+    while p * p <= n {
+        if n % p == 0 {
+            return false
+        }
+        p += 2
+        if n % p == 0 {
+            return false
+        }
+        p += 4
+    }
+    return true
+}
+
+func digitSum(_ num: Int) -> Int {
+    var sum = 0
+    var n = num
+    while n > 0 {
+        sum += n % 10
+        n /= 10
+    }
+    return sum
+}
+
+let limit = 500
+print("Additive primes less than \(limit):")
+var count = 0
+for n in 1..<limit {
+    if isPrime(digitSum(n)) && isPrime(n) {
+        count += 1
+        print(String(format: "%3d", n), terminator: count % 10 == 0 ? "\n" : " ")
+    }
+}
+print("\n\(count) additive primes found.")