Data commit

Task/Hofstadter-Q-sequence/Quackery/hofstadter-q-sequence.quackery

@@ -0,0 +1,32 @@
+[ 2dup swap size dup negate swap within
+    not if
+      [ drop size 1+ number$
+        $ "Term " swap join
+        $ " of the Q sequence is not defined."
+        join message put bail ]
+    peek ]                                is qpeek  ( [ n --> x )
+
+  [ dup dup -1 qpeek negate qpeek
+    dip [ dup dup -2 qpeek negate qpeek ]
+    + join ]                              is next-q (   [ --> [ )
+
+  [ dup size 2 < iff
+      [ drop 0 ] done
+    0 swap behead swap
+    witheach
+      [ tuck > if [ dip 1+ ] ]
+    drop ]                                is drops  (   [ --> n )
+
+  0 backup
+    [ ' [ 1 1 ]
+      998 times next-q
+      dup
+      -1 split swap 10 split drop
+      witheach [ echo sp ]
+      say "... "
+      0 peek echo cr
+      99000 times next-q
+      drops echo
+      say " decreasing terms" ]
+  bailed if
+    [ message take cr echo$ cr ]