Fraction reduction: Difference between revisions

=={{header|Visual Basic .NET}}==

{{trans|C#}}

<lang vbnet>Module Module1

Function IndexOf(n As Integer, s As Integer()) As Integer

For ii = 1 To s.Length

Dim i = ii - 1

If s(i) = n Then

Return i

End If

Next

Return -1

End Function

Function GetDigits(n As Integer, le As Integer, digits As Integer()) As Boolean

While n > 0

Dim r = n Mod 10

If r = 0 OrElse IndexOf(r, digits) >= 0 Then

Return False

End If

le -= 1

digits(le) = r

n \= 10

End While

Return True

End Function

Function RemoveDigit(digits As Integer(), le As Integer, idx As Integer) As Integer

Dim pows = {1, 10, 100, 1000, 10000}

Dim sum = 0

Dim pow = pows(le - 2)

For ii = 1 To le

Dim i = ii - 1

If i = idx Then

Continue For

End If

sum += digits(i) * pow

pow \= 10

Next

Return sum

End Function

Sub Main()

Dim lims = {{12, 97}, {123, 986}, {1234, 9875}, {12345, 98764}}

Dim count(5) As Integer

Dim omitted(5, 10) As Integer

Dim upperBound = lims.GetLength(0)

For ii = 1 To upperBound

Dim i = ii - 1

Dim nDigits(i + 2 - 1) As Integer

Dim dDigits(i + 2 - 1) As Integer

Dim blank(i + 2 - 1) As Integer

For n = lims(i, 0) To lims(i, 1)

blank.CopyTo(nDigits, 0)

Dim nOk = GetDigits(n, i + 2, nDigits)

If Not nOk Then

Continue For

End If

For d = n + 1 To lims(i, 1) + 1

blank.CopyTo(dDigits, 0)

Dim dOk = GetDigits(d, i + 2, dDigits)

If Not dOk Then

Continue For

End If

For nixt = 1 To nDigits.Length

Dim nix = nixt - 1

Dim digit = nDigits(nix)

Dim dix = IndexOf(digit, dDigits)

If dix >= 0 Then

Dim rn = RemoveDigit(nDigits, i + 2, nix)

Dim rd = RemoveDigit(dDigits, i + 2, dix)

If (n / d) = (rn / rd) Then

count(i) += 1

omitted(i, digit) += 1

If count(i) <= 12 Then

Console.WriteLine("{0}/{1} = {2}/{3} by omitting {4}'s", n, d, rn, rd, digit)

End If

End If

End If

Next

Next

Next

Console.WriteLine()

Next

For i = 2 To 5

Console.WriteLine("There are {0} {1}-digit fractions of which:", count(i - 2), i)

For j = 1 To 9

If omitted(i - 2, j) = 0 Then

Continue For

End If

Console.WriteLine("{0,6} have {1}'s omitted", omitted(i - 2, j), j)

Next

Console.WriteLine()

Next

End Sub

End Module</lang>

{{out}}

<pre>16/64 = 1/4 by omitting 6's

19/95 = 1/5 by omitting 9's

26/65 = 2/5 by omitting 6's

49/98 = 4/8 by omitting 9's

132/231 = 12/21 by omitting 3's

134/536 = 14/56 by omitting 3's

134/938 = 14/98 by omitting 3's

136/238 = 16/28 by omitting 3's

138/345 = 18/45 by omitting 3's

139/695 = 13/65 by omitting 9's

143/341 = 13/31 by omitting 4's

146/365 = 14/35 by omitting 6's

149/298 = 14/28 by omitting 9's

149/596 = 14/56 by omitting 9's

149/894 = 14/84 by omitting 9's

154/253 = 14/23 by omitting 5's

1234/4936 = 124/496 by omitting 3's

1239/6195 = 123/615 by omitting 9's

1246/3649 = 126/369 by omitting 4's

1249/2498 = 124/248 by omitting 9's

1259/6295 = 125/625 by omitting 9's

1279/6395 = 127/635 by omitting 9's

1283/5132 = 128/512 by omitting 3's

1297/2594 = 127/254 by omitting 9's

1297/3891 = 127/381 by omitting 9's

1298/2596 = 128/256 by omitting 9's

1298/3894 = 128/384 by omitting 9's

1298/5192 = 128/512 by omitting 9's

12349/24698 = 1234/2468 by omitting 9's

12356/67958 = 1236/6798 by omitting 5's

12358/14362 = 1258/1462 by omitting 3's

12358/15364 = 1258/1564 by omitting 3's

12358/17368 = 1258/1768 by omitting 3's

12358/19372 = 1258/1972 by omitting 3's

12358/21376 = 1258/2176 by omitting 3's

12358/25384 = 1258/2584 by omitting 3's

12359/61795 = 1235/6175 by omitting 9's

12364/32596 = 1364/3596 by omitting 2's

12379/61895 = 1237/6185 by omitting 9's

12386/32654 = 1386/3654 by omitting 2's

There are 4 2-digit fractions of which:

2 have 6's omitted

2 have 9's omitted

There are 122 3-digit fractions of which:

9 have 3's omitted

1 have 4's omitted

6 have 5's omitted

15 have 6's omitted

16 have 7's omitted

15 have 8's omitted

60 have 9's omitted

There are 660 4-digit fractions of which:

14 have 1's omitted

25 have 2's omitted

92 have 3's omitted

14 have 4's omitted

29 have 5's omitted

63 have 6's omitted

16 have 7's omitted

17 have 8's omitted

390 have 9's omitted

There are 5087 5-digit fractions of which:

75 have 1's omitted

40 have 2's omitted

376 have 3's omitted

78 have 4's omitted

209 have 5's omitted

379 have 6's omitted

591 have 7's omitted

351 have 8's omitted

2988 have 9's omitted</pre>