How to reorder string variable x factorial different ways?

[Circlotron]

Say I have a string variable abcd$. The letters in the variable can be arranged 4 factorial or 4x3x2x1 different ways. How can I produce every combination? Find Len(abcd$) then a for/next loop Len factorial times, but what inside the loop? I'm at a loss here.

[Kernelpanic]

Say I have a string variable abcd$. The letters in the variable can be arranged 4 factorial or 4x3x2x1 different ways. How can I produce every combination? Find Len(abcd$) then a for/next loop Len factorial times, but what inside the loop? I'm at a loss here.

This is the calculation of the factorial: n!

Code: (Select All)

'Fakultaet iterativ mit FOR-Schleife - 11. Feb. 2023



$Console:Only

Option _Explicit



Declare Function Fakultaet(n As Integer) As _Integer64



Dim As Integer n



Locate 2, 3

Print "Iterative Berechnung der Fakultaet - (n!)"



Locate 4, 3

Input "Fakultaet von (n): ", n



Locate 5, 3

Print Using "Die Fakultaet von ### ist: ###,###,###"; n, Fakultaet(n)



End 'Hauptprogramm





Function Fakultaet (n As Integer)



  Dim As _Integer64 fakul

  Dim As Integer i



  fakul = 1

  For i = 1 To n

    fakul = fakul * i

  Next



  Fakultaet = fakul

Oder in Julia:

[Circlotron]

Thanks for that. In the meantime I realised I was asking the wrong question. I'll start a new thread.

[bplus]

maybe you want every permutation, not combination as there are 4! permutations to abcd letters.

[SMcNeill]

Code: (Select All)

ReDim Shared WordList(0) As String

FactorIt "1234", ""

For i = 1 To UBound(WordList)

    Print WordList(i),

Next



Sub FactorIt (word$, seed$)

    For i = 1 To Len(word$)

        seed1$ = seed$ + Mid$(word$, i, 1)

        w$ = Left$(word$, i - 1) + Mid$(word$, i + 1)

        For k = 1 To UBound(WordList)

            If WordList(k) = seed1$ + w$ Then Exit For

        Next

        If k > UBound(WordList) Then

            ReDim _Preserve WordList(k) As String

            WordList(k) = seed1$ + w$

        End If

        FactorIt w$, seed1$

    Next

End Sub

FactorIt above generates a list of values, removing duplicates for you.   For example, "goo" has two "o"s, so it can only generate "goo", "ogo", "oog", and a few of those in duplicate which we don't count.

[Pete]

I tried running the string "THIS" in this FreeBASIC permutation algorithm, but it got stuck in an endless loop...

Code: (Select All)

Print "Find the permutations of the word: THIS."

a$ = "THIS"

Sleep 5

Do

    a = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 4

    b = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 2

    c = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 3

    d = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 1

    Print Mid$(a$, a, 1) + Mid$(a$, b, 1) + Mid$(a$, c, 1) + Mid$(a$, d, 1); " ";

    _Delay .02

Loop Until perm = 24

I'm thinking about emailing it to Clippy, as a screen saver.

Pete

[PhilOfPerth]

Say I have a string variable abcd$. The letters in the variable can be arranged 4 factorial or 4x3x2x1 different ways. How can I produce every combination? Find Len(abcd$) then a for/next loop Len factorial times, but what inside the loop? I'm at a loss here.

I' m currently working on a similar problem for one of my games (hope it's not the same game!) so I'll be interested to see what comes up from the gurus here.

---

I tried running the string "THIS" in this FreeBASIC permutation algorithm, but it got stuck in an endless loop...

Code: (Select All)

Print "Find the permutations of the word: THIS."

a$ = "THIS"

Sleep 5

Do

    a = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 4

    b = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 2

    c = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 3

    d = (Rnd * 3 Mod 4) * 365 / 4 ^ 7 + 1

    Print Mid$(a$, a, 1) + Mid$(a$, b, 1) + Mid$(a$, c, 1) + Mid$(a$, d, 1); " ";

    _Delay .02

Loop Until perm = 24

I'm thinking about emailing it to Clippy, as a screen saver.

Pete

Wow, wonder why that happens! 

[PhilOfPerth]

Code: (Select All)

ReDim Shared WordList(0) As String

FactorIt "1234", ""

For i = 1 To UBound(WordList)

    Print WordList(i),

Next



Sub FactorIt (word$, seed$)

    For i = 1 To Len(word$)

        seed1$ = seed$ + Mid$(word$, i, 1)

        w$ = Left$(word$, i - 1) + Mid$(word$, i + 1)

        For k = 1 To UBound(WordList)

            If WordList(k) = seed1$ + w$ Then Exit For

        Next

        If k > UBound(WordList) Then

            ReDim _Preserve WordList(k) As String

            WordList(k) = seed1$ + w$

        End If

        FactorIt w$, seed1$

    Next

End Sub

FactorIt above generates a list of values, removing duplicates for you.   For example, "goo" has two "o"s, so it can only generate "goo", "ogo", "oog", and a few of those in duplicate which we don't count.

Ahah! That's a (reasonably) simple solution to a problem I'm wrestling with at the moment! I had written a factorial-ising routine, but it was way too bulky and slow to be useful. I'll try to adapt this into my language ("dumb it down") and use it!

Edit: This worked when I used alpha chars, which is what I want) to do), but when I used anything longer than 7 characters, it gave no result.

Edit2: I was able to get results when I added this before the last Next, and remove the Print wordlist$(i)

Print wordlist(k);" ";

It's still very slow for more than 7 chars, but that may be enough (for mine, anyway). 87 sec for 8 characters.

[bplus]

Edit: This worked when I used alpha chars, which is what I want) to do), but when I used anything longer than 7 characters, it gave no result.

these are permutations, there are n! for n elements

N! = 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800, ....

that sequence expands faster than any x^n ie expedentially plus!

you propably didn't get results because you didn't wait long enough plus real easy to go beyond the limits of the type fairly quickly.

that routine steve provided i think was better than what i had, except maybe the non recursive one?

i filed the data for 10 letters or digits so i could use a substitution technique for 10 of anything without recalculating permutaions of 10 things because it takes so long.

[PhilOfPerth]

At the risk of hijacking  Circlotron's post further,     thanks @bplus. I was aware of the permutatins thing and its associated problem with expansion, but couldn't see a way around it.
Not sure what you meant in your last line, about filing the data... could you elaborate a little? It sounds interesting.