Add Prime Number in Red (#5177)

Author: DarienArthur-Gocken

archive/r/red/prime-number.red

@@ -0,0 +1,44 @@
+Red [Title: "Prime Number in Red"]
+
+prime-number: func [number [integer!]] [
+    either number <= 1 [
+        print "Composite"
+    ][
+        found?: false
+        limit: to integer! square-root number
+        repeat i limit - 1 [
+            if (number // (i + 1)) = 0 [
+                print "Composite"
+                found?: true
+                break
+            ]
+        ]
+        if not found? [print "Prime"]
+    ]
+]
+
+main: func [arg [string!]] [
+
+    arg: trim/with arg {'"}
+
+    digit: charset "0123456789"
+    if not parse arg [opt ["+" | "-"] some digit end] [
+        print "Usage: please input a non-negative integer"
+        exit
+    ]
+
+    either attempt [arg: to-integer arg][
+    ][
+        print "Usage: please input a non-negative integer"
+        exit
+    ]
+
+    if negative? arg [
+        print "Usage: please input a non-negative integer"
+        exit
+    ]
+
+    prime-number arg
+]
+
+main system/script/args