diff -r 939c10745a3a -r a10430cb797c progs/catastrophic/catastrophic.dart
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/catastrophic/catastrophic.dart	Wed Oct 07 09:08:55 2020 +0100
@@ -0,0 +1,23 @@
+/// A case of catastrophic backtracking in Dart
+///---------------------------------------------
+/// example provided by Martin Todorov
+///
+/// regex: (a*)*b
+/// strings: aa...a
+///
+/// run with
+///
+///    dart catastrophic.dart n
+
+
+main(List<String> args) {
+  final n = int.parse(args[0]);
+  final evilRegex = RegExp("(a*)*b");
+
+  for(int i = 1; i <= n; i++) {
+    final toMatch = "a" * i;
+    final stopwatch = Stopwatch()..start();
+    evilRegex.hasMatch(toMatch);
+    print("$i a's matched in ${stopwatch.elapsed}");
+  }
+}