Add Prime Number in Swift (#5348)

Author: Vidish3442

archive/s/swift/prime-number.swift

@@ -0,0 +1,32 @@
+import Foundation
+
+let usage = "Usage: please input a non-negative integer"
+
+if CommandLine.arguments.count != 2 {
+    print(usage)
+    exit(0)
+}
+
+guard let number = Int(CommandLine.arguments[1]), number >= 0 else {
+    print(usage)
+    exit(0)
+}
+
+if number < 2 {
+    print("composite")
+    exit(0)
+}
+
+var isPrime = true
+let limit = Int(Double(number).squareRoot())
+
+if limit >= 2 {
+    for i in 2...limit {
+        if number % i == 0 {
+            isPrime = false
+            break
+        }
+    }
+}
+
+print(isPrime ? "prime" : "composite")