September 2017 Update

Task/Hofstadter-Q-sequence/Scheme/hofstadter-q-sequence-1.ss

@@ -1,47 +0,0 @@
-(define qc '#(0 1 1))
-(define filled 3)
-(define len 3)
-
-;; chicken scheme: vector-resize!
-;; gambit: vector-append
-(define (extend-qc)
-  (let* ((new-len (* 2 len))
-	 (new-qc (make-vector new-len)))
-    (let copy ((n 0))
-      (if (< n len)
-	(begin
-	  (vector-set! new-qc n (vector-ref qc n))
-	  (copy (+ 1 n)))))
-    (set! len new-len)
-    (set! qc new-qc)))
-
-(define (q n)
-  (let loop ()
-    (if (>= filled len) (extend-qc))
-    (if (>= n filled)
-      (begin
-	(vector-set! qc filled (+ (q (- filled (q (- filled 1))))
-				  (q (- filled (q (- filled 2))))))
-	(set! filled (+ 1 filled))
-	(loop))
-      (vector-ref qc n))))
-
-(display "Q(1 .. 10): ")
-(let loop ((i 1))
-  ;; (print) behave differently regarding newline across compilers
-  (display (q i))
-  (display " ")
-  (if (< i 10)
-    (loop (+ 1 i))
-    (newline)))
-
-(display "Q(1000): ")
-(display (q 1000))
-(newline)
-
-(display "bumps up to 100000: ")
-(display
-  (let loop ((s 0) (i 1))
-    (if (>= i 100000) s
-      (loop (+ s (if (> (q i) (q (+ 1 i))) 1 0)) (+ 1 i)))))
-(newline)

Task/Hofstadter-Q-sequence/Scheme/hofstadter-q-sequence-2.ss

@@ -1,3 +0,0 @@
-Q(1 .. 10): 1 1 2 3 3 4 5 5 6 6
-Q(1000): 502
-bumps up to 100000: 49798