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Active Forums => Programs => Topic started by: TempodiBasic on April 11, 2021, 05:26:27 pm

Title: a reverse string (Rosetta Code)
Post by: TempodiBasic on April 11, 2021, 05:26:27 pm
Hi Guys and Gals of QB64 community

here a demo written for the task of rosetta code http://www.rosettacode.org/wiki/Reverse_a_string (http://www.rosettacode.org/wiki/Reverse_a_string)

Code: QB64: [Select]
  1. 'reverse a string
  3.  
  4. A = "Hello World!"
  5. Print A, Reverse1$(A)
  6. A = "This is QB64"
  7. Print A, Reverse2$(A)
  8. A = "QB64 is Powerful!"
  9. Print A, Reverse3$(A)
  11.  
  12. Function Reverse1$ (A As String)
  13.     Dim ReverseA As String
  14.     Dim As Integer Alenght, countFor
  15.  
  16.     Alenght = Len(A)
  17.     For countFor = 1 To Alenght Step 1
  18.         ReverseA = ReverseA + Right$(A, 1)
  19.         A = Left$(A, Alenght - countFor)
  20.     Next countFor
  21.     Reverse1$ = ReverseA
  23.  
  24. Function Reverse2$ (A As String)
  25.     Dim ReverseA As String, B As String
  26.     Dim As Integer Alenght, countFor
  27.     Alenght = Len(A)
  28.     B = A
  29.     For countFor = 1 To Alenght Step 1
  30.         B = Right$(A, countFor)
  31.         ReverseA = ReverseA + Left$(B, 1)
  32.     Next countFor
  33.     Reverse2$ = ReverseA
  35.  
  36. Function Reverse3$ (A As String)
  37.     Dim ReverseA As String
  38.     Dim As Integer Alenght, countFor
  39.  
  40.     Alenght = Len(A)
  41.     For countFor = Alenght To 1 Step -1
  42.         ReverseA = ReverseA + Mid$(A, countFor, 1)
  43.     Next countFor
  44.     Reverse3$ = ReverseA
  46.  

Please run to test o post a benchmark so we can publish this on website.
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 11, 2021, 06:11:20 pm
Code: QB64: [Select]
  1. s$ = "reverse"
  2. For i = Len(s$) To 1 Step -1
  3.     Print Mid$(s$, i, 1);
  5.  
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 11, 2021, 06:25:35 pm
Code: QB64: [Select]
  1. r$ = "Here is a cool one!" ' b+ Recursive reverse trans QB64 2021-04-11
  2. Print reverse$(r$)
  3. Function reverse$ (s As String)
  4.     If Len(s) = 1 Then reverse$ = s Else revs$ = reverse$(Mid$(s, 2)) + Left$(s, 1)
  6.  
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 11, 2021, 06:33:50 pm
Code: QB64: [Select]
  1. r$ = "Here is another one without concatenation." ' b+ reverse 2021-04-11
  2. Print reverse$(r$)
  3. Function reverse$ (s As String)
  4.     reverse$ = Space$(Len(s))
  5.     For i = Len(s) To 1 Step -1
  6.         Mid$(reverse$, Len(s) + 1 - i, 1) = Mid$(s, i, 1)
  7.     Next
  9.  
Title: Re: a reverse string (Rosetta Code)
Post by: TempodiBasic on April 11, 2021, 06:42:42 pm
Hi Bplus
I find cool the shortest reverse task!
I think that it is good to show different ways to get the task using different keywords, so MID$ together RIGHT$ and LEFT$ can be a good team.
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 11, 2021, 06:54:07 pm
Quote from: TempodiBasic on April 11, 2021, 06:42:42 pm
Hi Bplus
I find cool the shortest reverse task!
I think that it is good to show different ways to get the task using different keywords, so MID$ together RIGHT$ and LEFT$ can be a good team.

Yes! :)
Code: QB64: [Select]
  1. r$ = "reverse"
  3. reverse r$
  4. Sub reverse (r$)
  5.     For i = Len(r$) To 1 Step -1
  6.         Locate 2, Len(r$) - i + 1: Print Chr$(Screen(1, i))
  7.     Next
  9.  
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 11, 2021, 06:57:02 pm
Oh this is better:
Code: QB64: [Select]
  1. r$ = "This is better."
  3. reverse r$
  4. Sub reverse (r$)
  5.     For i = Len(r$) To 1 Step -1
  6.         Locate 1, Len(r$) + 1 + Len(r$) - i + 1: Print Chr$(Screen(1, i))
  7.     Next
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 11, 2021, 07:09:30 pm
Here is a fun one!

Code: QB64: [Select]
  1. _Title "Please enter a string to reverse..."
  2. While _KeyDown(27) = 0 And _KeyDown(13) = 0
  3.     k$ = InKey$
  4.     If Len(k$) Then
  5.         If Asc(k$) = 8 Then temp$ = Mid$(temp$, 2) Else temp$ = k$ + temp$
  6.         Cls
  7.         Print temp$
  8.     End If
  9.     _Limit 10
  11.  
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 11, 2021, 07:40:18 pm
This one is fun to watch!
Code: QB64: [Select]
  1. r$ = "0123456789"
  2. reverse r$
  3. Sub reverse (r$)
  4.     Print r$
  5.     k = 2
  6.     While k <= Len(r$)
  7.         For i = Len(r$) To k Step -1
  8.             t$ = Mid$(r$, i, 1)
  9.             Mid$(r$, i, 1) = Mid$(r$, i - 1, 1)
  10.             Mid$(r$, i - 1, 1) = t$
  11.             Locate 2, 1: Print r$
  12.             _Limit 1
  13.         Next
  14.         k = k + 1
  15.     Wend
  17.  
Title: Re: a reverse string (Rosetta Code)
Post by: euklides on April 12, 2021, 03:22:16 am
a$ = "reverse": b$ = "": FOR x = 1 TO LEN(a$): b$ = MID$(a$, x, 1) + b$: NEXT x: PRINT b$: SLEEP 
Title: Re: a reverse string (Rosetta Code)
Post by: SpriggsySpriggs on April 13, 2021, 11:03:41 am
Here is my version of this challenge, using @TempodiBasic 's suggestion of functions and subs having the same name:

Code: QB64: [Select]
  2.  
  4.  
  5. test = "This is a test!"
  6.  
  7. Print Reverse(test)
  8. Print test
  9. Reverse test
  10. Print test
  11.  
  12. Function Reverse$ (rev As String)
  13.     Dim As String s: s = rev
  14.     Dim As String * 1 sArr(0 To Len(s))
  17.     n = Len(s) + 1
  18.     For i = LBound(sArr) To UBound(sArr)
  19.         sArr(i) = Mid$(s, i, 1)
  20.     Next
  21.     For i = 0 To (n / 2) - 1
  22.         Swap sArr(i), sArr(n - i - 1)
  23.     Next
  24.     s = ""
  25.     For i = LBound(sArr) To UBound(sArr) - 1
  26.         s = s + sArr(i)
  27.     Next
  28.     Reverse = s
  30.  
  31. Sub Reverse (s As String)
  32.     Dim As String * 1 sArr(0 To Len(s))
  35.     n = Len(s) + 1
  36.     For i = LBound(sArr) To UBound(sArr)
  37.         sArr(i) = Mid$(s, i, 1)
  38.     Next
  39.     For i = 0 To (n / 2) - 1
  40.         Swap sArr(i), sArr(n - i - 1)
  41.     Next
  42.     s = ""
  43.     For i = LBound(sArr) To UBound(sArr) - 1
  44.         s = s + sArr(i)
  45.     Next

 
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 13, 2021, 12:57:17 pm
Oh here is my best yet!
Code: QB64: [Select]
  1. _Title "Reverse Everything!" 'b+ 2021-04-13
  2.  
  3. Screen _NewImage(216, 64, 32)
  4. _Delay .25 'need time for screen to load before attempting to move it.
  6.  
  7. Locate 2, 11: Print "reverse"
  8. _PutImage (0, 32), 0, 0, (214, 16)-Step(-216, 16)
  10.  

 


Edit: seemed a pixel off in first screen shot, so I moved over.
Title: Re: a reverse string (Rosetta Code)
Post by: SpriggsySpriggs on April 13, 2021, 03:11:50 pm
And another version. I know, not really QB64.

Code: C++: [Select]
  1. //save this as reverse.h
  2. #include <bits/stdc++.h>
  3. const char* ReverseString(const char* str){
  4.         std::string str2 = str;
  5.         reverse(str2.begin(),str2.end());
  6.         return str2.c_str();
  7. }

Code: QB64: [Select]
  2.  
  4.     Function Reverse$ Alias "ReverseString" (str As String)
  6.  
  7. Print Reverse("This is a test")
Title: Re: a reverse string (Rosetta Code)
Post by: TempodiBasic on April 13, 2021, 05:44:16 pm
Hey boys
the challange on new ways to do a reverse string is being interesting!
Title: Re: a reverse string (Rosetta Code)
Post by: bplus on April 13, 2021, 06:46:27 pm
And another one!
Code: QB64: [Select]
  1. _Title "Swinging Reverse" 'b+ 2021-04-13
  2.  
  3. Screen _NewImage(216, 64, 32)
  4. _Delay .25 'need time for screen to load before attempting to move it.
  6. xc = _Width / 2: yc = _Height / 2
  8. _PrintString (xc - 7 * 4, yc - 8), "reverse"
  9. _PutImage , 0, r&
  10. xs = 4: dx = -.1
  12.     Cls
  13.     RotoZoom3 xc, yc, r&, xs, 4, 0
  14.     xs = xs + dx
  15.     If xs < -4 Then xs = -4: dx = -dx
  16.     If xs > 4 Then xs = 4: dx = -dx
  17.     _Display
  18.     _Limit 30
  20.  
  21. Sub RotoZoom3 (X As Long, Y As Long, Image As Long, xScale As Single, yScale As Single, radianRotation As Single) ' 0 at end means no scaling of x or y
  22.     Dim px(3) As Single: Dim py(3) As Single
  23.     Dim W&, H&, sinr!, cosr!, i&, x2&, y2&
  24.     W& = _Width(Image&): H& = _Height(Image&)
  25.     px(0) = -W& / 2: py(0) = -H& / 2: px(1) = -W& / 2: py(1) = H& / 2
  26.     px(2) = W& / 2: py(2) = H& / 2: px(3) = W& / 2: py(3) = -H& / 2
  27.     sinr! = Sin(-radianRotation): cosr! = Cos(-radianRotation)
  28.     For i& = 0 To 3
  29.         x2& = xScale * (px(i&) * cosr! + sinr! * py(i&)) + X: y2& = yScale * (py(i&) * cosr! - px(i&) * sinr!) + Y
  30.         px(i&) = x2&: py(i&) = y2&
  31.     Next
  32.     _MapTriangle _Seamless(0, 0)-(0, H& - 1)-(W& - 1, H& - 1), Image To(px(0), py(0))-(px(1), py(1))-(px(2), py(2))
  33.     _MapTriangle _Seamless(0, 0)-(W& - 1, 0)-(W& - 1, H& - 1), Image To(px(0), py(0))-(px(3), py(3))-(px(2), py(2))
  35.  
  36.  
Title: Re: a reverse string (Rosetta Code)
Post by: TempodiBasic on April 21, 2021, 07:29:00 pm
Hi guys
I'm very fine to see how the challange has been brought far,
now I'll be finer to get common evaluation about what code covers very well the Rosetta tasks
Think about publishing on that website to show how QB64  is  versatle
Title: Re: a reverse string (Rosetta Code)
Post by: George McGinn on April 21, 2021, 11:13:32 pm
You should. There are very few QB64 solutions posted.

I have published several of my solutions there, in a few languages (QB64, TechBASIC and R).

If you want, I can post the template needed to add to the Rosetta pages.

Let me know.


Title: Re: a reverse string (Rosetta Code)
Post by: TempodiBasic on April 22, 2021, 07:31:38 pm
Yesterday I have posted 3 solutions already showed in this forum
for now I have copied the header and the <lang>  </lang>

You're kind to offer a template, it will  be useful. I accept your offert. Thanks
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