Data commit

Task/Hofstadter-Figure-Figure-sequences/APL/hofstadter-figure-figure-sequences.apl

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+:Class HFF
+    :Field Private Shared RBuf←,1
+    ∇r←ffr n
+        :Access Public Shared
+        r←n⊃RBuf←(⊢,⊃∘⌽+≢⊃(⍳1+⌈/)~⊢)⍣(0⌈n-≢RBuf)⊢RBuf
+    ∇
+    ∇s←ffs n;S
+        :Access Public Shared
+        :Repeat
+            S←((⍳1+⌈/)~⊢)RBuf
+            :If n≤≢S ⋄ :Leave ⋄ :EndIf
+            S←ffr 1+≢RBuf
+        :EndRepeat
+        s←n⊃S
+    ∇
+    ∇Task;th
+        :Access Public Shared
+        ⎕←'R(1 .. 10):', ffr¨⍳10
+        :If (⍳1000) ∧.∊ ⊂th←(ffr¨⍳40) ∪ (ffs¨⍳960)
+            ⎕←'1..1000 ∊ (ffr 1..40) ∪ (ffs 1..960)'
+        :Else
+            ⎕←'Missing values: ', (⍳1000)~th
+        :EndIf
+    ∇
+:EndClass