Data commit

Task/Hofstadter-Figure-Figure-sequences/VBA/hofstadter-figure-figure-sequences.vba

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+Private Function ffr(n As Long) As Long
+    Dim R As New Collection
+    Dim S As New Collection
+    R.Add 1
+    S.Add 2
+    'return R(n)
+    For i = 2 To n
+        R.Add R(i - 1) + S(i - 1)
+        For j = S(S.Count) + 1 To R(i) - 1
+            S.Add j
+        Next j
+        For j = R(i) + 1 To R(i) + S(i - 1)
+            S.Add j
+        Next j
+    Next i
+    ffr = R(n)
+    Set R = Nothing
+    Set S = Nothing
+End Function
+Private Function ffs(n As Long) As Long
+    Dim R As New Collection
+    Dim S As New Collection
+    R.Add 1
+    S.Add 2
+    'return S(n)
+    For i = 2 To n
+        R.Add R(i - 1) + S(i - 1)
+        For j = S(S.Count) + 1 To R(i) - 1
+            S.Add j
+        Next j
+        For j = R(i) + 1 To R(i) + S(i - 1)
+            S.Add j
+        Next j
+        If S.Count >= n Then Exit For
+    Next i
+    ffs = S(n)
+    Set R = Nothing
+    Set S = Nothing
+End Function
+Public Sub main()
+    Dim i As Long
+    Debug.Print "The first ten values of R are:"
+    For i = 1 To 10
+        Debug.Print ffr(i);
+    Next i
+    Debug.Print
+    Dim x As New Collection
+    For i = 1 To 1000
+        x.Add i, CStr(i)
+    Next i
+    For i = 1 To 40
+        x.Remove CStr(ffr(i))
+    Next i
+    For i = 1 To 960
+        x.Remove CStr(ffs(i))
+    Next i
+    Debug.Print "The first 40 values of ffr plus the first 960 values of ffs "
+    Debug.Print "include all the integers from 1 to 1000 exactly once is "; Format(x.Count = 0)
+End Sub