Data commit

Task/Mian-Chowla-sequence/VBScript/mian-chowla-sequence-1.vb

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+' Mian-Chowla sequence - VBScript - 15/03/2019
+    Const m = 100, mm=28000
+    ReDim r(mm), v(mm * 2)
+    Dim n, t, i, j, l, s1, s2, iterate_t
+    ReDim seq(m)
+    t0=Timer
+    s1 = "1": s2 = ""
+    seq(1) = 1: n = 1: t = 1
+    Do While n < m
+        t = t + 1
+        iterate_t = False
+        For i = 1 to t * 2
+            v(i) = 0
+        Next
+        i = 1
+        Do While i <= t And Not iterate_t
+            If r(i) = 0 Then
+                j = i
+                Do While j <= t And Not iterate_t
+                    If r(j) = 0 Then
+                        l = i + j
+                        If v(l) = 1 Then
+                            r(t) = 1
+                            iterate_t = True
+                        End If
+                        If Not iterate_t Then v(l) = 1
+                    End If
+                    j = j + 1
+                Loop
+            End If
+            i = i + 1
+        Loop
+        If Not iterate_t Then
+            n = n + 1
+            seq(n) = t
+            if           n<= 30 then s1 = s1 & " " & t
+            if n>=91 and n<=100 then s2 = s2 & " " & t
+        End If
+    Loop
+    wscript.echo "t="& t
+    wscript.echo "The Mian-Chowla sequence for elements 1 to 30:"
+    wscript.echo s1
+    wscript.echo "The Mian-Chowla sequence for elements 91 to 100:"
+    wscript.echo s2
+    wscript.echo "Computation time: "&  Int(Timer-t0) &" sec"

Task/Mian-Chowla-sequence/VBScript/mian-chowla-sequence-2.vb

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+' Mian-Chowla sequence - VBScript - March 19th, 2019
+
+    Function Find(x(), val) ' finds val on a pre-sorted list
+        Dim l, u, h : l = 0 : u = ubound(x) : Do : h = (l + u) \ 2
+            If val = x(h) Then Find = h : Exit Function
+            If val > x(h) Then l = h + 1 Else u = h - 1
+        Loop Until l > u : Find = -1
+    End Function
+
+    ' adds next item from a() to result (r()), adds all remaining items
+    ' from b(), once a() is exhausted
+    Sub Shuffle(ByRef r(), a(), b(), ByRef i, ByRef ai, ByRef bi, al, bl)
+        r(i) = a(ai) : ai = ai + 1 : If ai > al Then Do : i = i + 1 : _
+            r(i) = b(bi) : bi = bi + 1 : Loop until bi = bl
+    End Sub
+
+    Function Merger(a(), b(), bl) ' merges two pre-sorted lists
+        Dim res(), ai, bi, i : ReDim res(ubound(a) + bl) : ai = 0 : bi = 0
+        For i = 0 To ubound(res)
+            If a(ai) < b(bi) Then Shuffle res, a, b, i, ai, bi, ubound(a), bl _
+            Else Shuffle res, b, a, i, bi, ai, bl, ubound(a)
+        Next : Merger = res
+    End Function
+
+    Const n = 100 : Dim mc(), sums(), ts(), sp, tc : sp = 1 : tc = 0
+    ReDim mc(n - 1), sums(0), ts(n - 1) : mc(0) = 1 : sums(sp - 1) = 2
+    Dim sum, i, j, k, st : st = Timer
+    wscript.echo "The Mian-Chowla sequence for elements 1 to 30:"
+    wscript.stdout.write("1 ")
+    For i = 1 To n - 1 : j = mc(i - 1) + 1 : Do
+            mc(i) = j : For k = 0 To i
+                sum = mc(k) + j : If Find(sums, sum) >= 0 Then _
+                    tc = 0 : Exit For Else ts(tc) = sum : tc = tc + 1
+            Next : If tc > 0 Then
+              nu = Merger(sums, ts, tc) : ReDim sums(ubound(nu))
+              For e = 0 To ubound(nu) : sums(e) = nu(e) : Next
+              tc = 0 : Exit Do
+            End If : j = j + 1 : Loop
+        if i = 90 then wscript.echo vblf & vbLf & _
+            "The Mian-Chowla sequence for elements 91 to 100:"
+        If i < 30 or i >= 90 Then wscript.stdout.write(mc(i) & " ")
+    Next
+    wscript.echo vblf & vbLf & "Computation time: "& Timer - st &" seconds."