September 2017 Update

Task/Non-continuous-subsequences/Jq/non-continuous-subsequences-1.jq

@@ -0,0 +1,16 @@
+# Generate a stream of subsets of the input array
+def subsets:
+  if length == 0 then []
+  else .[0] as $first
+    | (.[1:] | subsets)
+    | ., ([$first] + .)
+  end ;
+
+# Generate a stream of non-continuous indices in the range 0 <= i < .
+def non_continuous_indices:
+  [range(0;.)] | subsets
+  | select(length > 1 and length != 1 + .[length-1] - .[0]) ;
+
+def non_continuous_subsequences:
+  (length | non_continuous_indices) as $ix
+  | [.[ $ix[] ]] ;

Task/Non-continuous-subsequences/Jq/non-continuous-subsequences-2.jq

@@ -0,0 +1,3 @@
+def count(f): reduce f as $i (0; . + 1);
+
+count( [range(0;20)] | non_continuous_subsequences)