Data update

Task/Circular-primes/PascalABC.NET/circular-primes.pas

@@ -0,0 +1,25 @@
+##
+function IsPrime(n: integer): boolean;
+begin
+  result := false;
+  for var i := 2 to n.Sqrt.Floor do
+    if n mod i = 0 then
+      exit;
+  result := true;
+end;
+
+function rotations(n: integer): sequence of integer;
+begin
+  var a := n.tostring;
+  for var i := 1 to a.Length do
+    yield (a[i:] + a[:i]).ToInteger;
+end;
+
+function isCircular(n: integer): boolean;
+begin
+  var rot := rotations(n);
+  if rot.first = rot.min then
+    result := rot.All(x -> isPrime(x));
+end;
+
+(2..1000_000).Where(x -> isCircular(x)).Take(19).Println;