Data update

Task/Non-continuous-subsequences/PascalABC.NET/non-continuous-subsequences.pas

@@ -0,0 +1,29 @@
+function AllSubSets<T>(a: List<T>; i: integer; lst: List<T>): sequence of List<T>;
+begin
+  if i = a.Count then yield lst
+  else
+  begin
+    lst.Add(a[i]);
+    yield sequence AllSubSets(a, i + 1, lst);
+    lst.RemoveAt(lst.Count - 1);
+    yield sequence AllSubSets(a, i + 1, lst);
+  end;
+end;
+
+function IsContinuous(lst: List<integer>) :=
+if lst.Count > 0 then lst[^1] - lst[0] + 1 = lst.Count else true;
+
+function ncsub<T>(seq: list<T>) :=
+Allsubsets(Lst(1..seq.Count), 0, new List<integer>)
+                                   .Where(s -> not iscontinuous(s))
+                                   .Select(s -> s.Select(i -> seq[i - 1]).ToList);
+
+begin
+  var seq := |'C', 'D', 'A', 'E', 'B'|.ToList;
+  println('Non-continuous subsequences for', seq, ':');
+  ncsub(seq).Println;
+  println;
+  println('Non-continuous subsequences:');
+  for var n := 1 to 20 do
+    println([1..n], '=', ncsub([1..n].ToList).Count);
+end.