Print Page - Number inversion

Is it possible in Ti Nspire by any mean to transform a number into its reverse like this:
EX: 103 --> 301?

Creating a program (either with Program Editor or LUA) should be possible to mirror the numbers

Thats the idea but i have no clue how to start the program really i'm blind here...

This will work regardless of language:

Final = 0
Reps = int(log(Num))
for (A, 0, Reps)
   Next = int(Num / 10)
   Final = Final * 10 + Num - 10*Next
   Num = Next

Your program adds a zero to the end of the number penguin.

Quote from: ElementCoder on November 13, 2012, 01:35:10 pm

Your program adds a zero to the end of the number penguin.

I guess it all depends on how your for loop works. But I fixed it to work on calculators.

Quote from: thepenguin77 on November 13, 2012, 01:39:16 pm

Quote from: ElementCoder on November 13, 2012, 01:35:10 pm
Your program adds a zero to the end of the number penguin.
I guess it all depends on how your for loop works. But I fixed it to work on calculators.

Maybe it differs from platform to platform? Anyway it can easily be cut off by dividing final by 10 when done.
On topic, here's your program in it's entire form joao9856:
Program style:

Code: [Select]

Define reverse(num)=
Prgm
    Local final,reps,next,a
    final:=0
    reps:=int(log(num,10))+1
    For a,0,reps
        next:=int(((num)/(10)))
        final:=final*10+num-10*next
        num:=next
    EndFor
    result = final/10
    Disp result
EndPrgm

Function style:

Code: [Select]

Define reversefunc(num)=
Func
Local final,reps,next,a
final:=0
reps:=int(log(num,10))+1
For a,0,reps
    next:=int(((num)/(10)))
    final:=final*10+num-10*next
    num:=next
EndFor
Return ((final)/(10))
EndFunc

If you just want to print the reversed number, use the program. If you want to perform arithmetic or something else with the reversed number use the function.

thanks guys!

No problem :) Also welcome to omni did you introduce (http://www.omnimaga.org/index.php?board=10.0) yourself to get your free bag of !peanuts?
Heh, I should thank you too penguin. Just found out it comes in very handy in my project :P

I just want to point out that since you're working with numbers (and not strings), any leading zeros won't come into effect (e.g. reverse(00123) will get you "321" and not "32100" (though the zeros disappear the moment you hit enter).

Also, that program will throw an error with numbers less or equal than 0 (because of log), but I suppose that's not part of the problem of mirroring numbers...

Oh you're right someone... I'll have a look into this tonight to find out what string manipulations tools we have again.

Code: [Select]

Define reverse()=
Prgm
    Local reverse,n,a
    RequestStr “ ”,a
    n:=dim(a)
   reverse:=mid(a,n,1) 
    For x,1,n-1
    reverse:= reverse& reverse:=mid(a,n-x,1)
    EndFor
    reverse:=expr(reverse)
    Disp reverse
EndPrgm

Alternatively, you could just type the string into the parentheses at the beginning, with the quotation marks
Also, you could output as a string, by removing the reverse:=expr(reverse), this won’t work with 321000

Is there any way of making this code run faster(i'm kinda newb here!)

Code: [Select]

Define LibPub inversor()=
Prgm
:Local final,reps,next,a
:f:=103
:Lbl g
:num:=f
:final:=0
:reps:=int(log(num,10))+1
:For a,0,reps
:next:=int(((num)/(10)))
:final:=final*10+num-10*next
:num:=next
:EndFor
:resulti:=((final)/(10))
:num:=resulti-f
:l:=num
:Disp "O Inverso de ",f," é ",resulti," logo:"
:Disp resulti,"-",f,"=",l
:Local final,reps,next,a
:final:=0
:reps:=int(log(num,10))+1
:For a,0,reps
:next:=int(((num)/(10)))
:final:=final*10+num-10*next
:num:=next
:EndFor
:resultii:=((final)/(10))
:Disp "O inverso de ",l," é ",resultii," logo:"
:Disp resultii,"+",l,"=",resultii+l
:Lbl e
:f:=f+1
:If f≥998 Then
:Goto h
:ElseIf f≥103 and f≤109 Then
:Goto g
:ElseIf f≥113 and f≤119 Then
:Goto g
:ElseIf f≥123 and f≤129 Then
:Goto g
:ElseIf f≥133 and f≤139 Then
:Goto g
:ElseIf f≥143 and f≤149 Then
:Goto g
:ElseIf f≥153 and f≤159 Then
:Goto g
:ElseIf f≥163 and f≤169 Then
:Goto g
:ElseIf f≥173 and f≤179 Then
:Goto g
:ElseIf f≥183 and f≤189 Then
:Goto g
:ElseIf f≥193 and f≤199 Then
:Goto g
:ElseIf f≥204 and f≤209 Then
:Goto g
:ElseIf f≥214 and f≤219 Then
:Goto g
:ElseIf f≥224 and f≤229 Then
:Goto g
:ElseIf f≥234 and f≤239 Then
:Goto g
:ElseIf f≥244 and f≤249 Then
:Goto g
:ElseIf f≥254 and f≤259 Then
:Goto g
:ElseIf f≥264 and f≤269 Then
:Goto g
:ElseIf f≥274 and f≤279 Then
:Goto g
:ElseIf f≥284 and f≤289 Then
:Goto g
:ElseIf f≥294 and f≤299 Then
:Goto g
:ElseIf f≥305 and f≤309 Then
:Goto g
:ElseIf f≥315 and f≤319 Then
:Goto g
:ElseIf f≥325 and f≤329 Then
:Goto g
:ElseIf f≥335 and f≤339 Then
:Goto g
:ElseIf f≥345 and f≤349 Then
:Goto g
:ElseIf f≥355 and f≤359 Then
:Goto g
:ElseIf f≥365 and f≤369 Then
:Goto g
:ElseIf f≥375 and f≤379 Then
:Goto g
:ElseIf f≥385 and f≤389 Then
:Goto g
:ElseIf f≥395 and f≤399 Then
:Goto g
:ElseIf f≥406 and f≤409 Then
:Goto g
:ElseIf f≥416 and f≤419 Then
:Goto g
:ElseIf f≥426 and f≤429 Then
:Goto g
:ElseIf f≥436 and f≤439 Then
:Goto g
:ElseIf f≥446 and f≤449 Then
:Goto g
:ElseIf f≥456 and f≤459 Then
:Goto g
:ElseIf f≥466 and f≤469 Then
:Goto g
:ElseIf f≥476 and f≤479 Then
:Goto g
:ElseIf f≥486 and f≤489 Then
:Goto g
:ElseIf f≥496 and f≤499 Then
:Goto g
:ElseIf f≥507 and f≤509 Then
:Goto g
:ElseIf f≥517 and f≤519 Then
:Goto g
:ElseIf f≥527 and f≤529 Then
:Goto g
:ElseIf f≥537 and f≤539 Then
:Goto g
:ElseIf f≥547 and f≤549 Then
:Goto g
:ElseIf f≥557 and f≤559 Then
:Goto g
:ElseIf f≥567 and f≤569 Then
:Goto g
:ElseIf f≥577 and f≤579 Then
:Goto g
:ElseIf f≥587 and f≤589 Then
:Goto g
:ElseIf f≥597 and f≤599 Then
:Goto g
:ElseIf f≥608 and f≤609 Then
:Goto g
:ElseIf f≥618 and f≤619 Then
:Goto g
:ElseIf f≥628 and f≤629 Then
:Goto g
:ElseIf f≥638 and f≤639 Then
:Goto g
:ElseIf f≥648 and f≤649 Then
:Goto g
:ElseIf f≥658 and f≤659 Then
:Goto g
:ElseIf f≥668 and f≤669 Then
:Goto g
:ElseIf f≥678 and f≤679 Then
:Goto g
:ElseIf f≥688 and f≤689 Then
:Goto g
:ElseIf f≥698 and f≤699 Then
:Goto g
:ElseIf f=709 Then
:Goto g
:ElseIf f=719 Then
:Goto g
:ElseIf f=729 Then
:Goto g
:ElseIf f=739 Then
:Goto g
:ElseIf f=749 Then
:Goto g
:ElseIf f=759 Then
:Goto g
:ElseIf f=769 Then
:Goto g
:ElseIf f=779 Then
:Goto g
:ElseIf f=789 Then
:Goto g
:ElseIf f=799 Then
:Goto g
:Else
:Goto e
:EndIf
:Lbl h
:EndPrgm

The language is portuguese and its says like this:
301 is the mirror for 103 then:
301-103=198
891 is the mirror for 198 then:
891+198=1089
and so on..

I would condense all your if/elseif <condition> goto g's into one large if statement. So

Code: [Select]

if <contition> or <condidtion> ...
goto g
else
goto e
end

I would also suggest not using goto/label, they can cause memory leaks in most languages.

so how do i avoid goto/label?

If the goto is to repeat the process or end it, you could call the function again inside the code (recursion) or end it using a return.

Code: [Select]

Local final,reps,next,a
f=103
while f!=998
 num=f
 final=0
 reps=int(log(num,10))+1
 For a,0,reps
  next=int(((num)/(10)))
  final=final*10+num-10*next
  num=next
 EndFor
 resulti=((final)/(10))
 num=resulti-f
 l=num
 Disp "O Inverso de ",f," é ",resulti," logo"
 Disp resulti,"-",f,"=",l
 Local final,reps,next,a
 final=0
 reps=int(log(num,10))+1
 For a,0,reps
  next=int(((num)/(10)))
  final=final*10+num-10*next
  num=next
 EndFor
 resultii=((final)/(10))
 Disp "O inverso de ",l," é ",resultii," logo"
 Disp resultii,"+",l,"=",resultii+l
 while !<reasons>
  f=f+1
 EndWhile
EndWhile

This would probably work. replace <reasons> with all the checks. Also, keep in mind this is psuedo code, it might need some altering to work.

Quote from: joao9856 on November 15, 2012, 11:34:29 am

Is there any way of making this code run faster(i'm kinda newb here!)

The language is Portuguese and its says like this:
301 is the mirror for 103 then:
301-103=198
891 is the mirror for 198 then:
891+198=1089
and so on..

Something I don't understand is the criteria to stop the program. The first time you do a subtraction of abs(mirror(number)-number) and then you do the same but with an addition over and over? ( abs(mirror(number)+number) ). How many times should it go before stopping?

BTW, if you create a function rather than a program, you can use the output as the next input (either with another function/program or in the Calculator). You could even place it under MyLib & have your own function:

Code: [Select]

Define LibPub mirror(input)=
Func
©mirror(input) mirrors "input" -> "tupni"
Local flip,n,i
  input:=string(input)
  n:=dim(input)
  flip:=mid(input,n,1)
  For i,1,n-1
    flip:=flip&mid(input,n-i,1)
  EndFor
  Return expr(flip)
EndFunc

If is only a subtraction, then sooner or later should stop in 0 (when the number is a palindrome). Something you can do using the calculator (with the code posted) could be:
* Type first the number you want to use as "ans", e.g. "103"
* Type "abs(mirror(ans)-ans)"
* hit enter several times until you reach 0

The idea is in the spoiler, i think that is all i wanna do( need to check mannually *.* all of it)
Its a pretty huge print for a calc to make but i always liked things big.
the idea is to see if every number mirror plus its mirror gives 1089.
rules are:
The smallest number must be 103
The number must not be equally read from the beginning to the and or from the the to the beginning(If they were it wouldn't make sense to mirror them)
The first number decides the biggest last number EX: if the first number is 4 the smallest last number can only be 6(allways up to 9)) or be it n+2 for the smallest.
And if i'm not mistaken thats it!
The SPOILER IS HUGE!

Spoiler For Spoiler:

Quote from: joao9856 on November 15, 2012, 03:20:39 pm

The idea is in the spoiler, i think that is all i wanna do( need to check manually *.* all of it)
Its a pretty huge print for a calc to make but i always liked things big.
the idea is to see if every number mirror plus its mirror gives 1089.

rules are:
The smallest number must be 103
The number must not be equally read from the beginning to the and or from the the to the beginning(If they were it wouldn't make sense to mirror them)
The first number decides the biggest last number EX: if the first number is 4 the smallest last number can only be 6(allways up to 9)) or be it n+2 for the smallest.
And if i'm not mistaken thats it!

Well, not every number satisfy the condition, e.g. 998 is not a palindrome (a number that is the same if read left to right or right to left).

If you use the code I posted earlier (which I called "mirror()"), you can print something like in the spoiler with the following function:

Code: [Select]

Define main()=
Func
  Local i,r1,r2,minus,plus
  For i,100,999
    r1:=mirror(i)
    minus:=abs(r1-i)
    r2:=mirror(minus)
    plus:=r2+minus
    If plus=1089 Then
      Disp "O Inverso de",i," é ",r1,"logo:"
      Disp max(r1,i),"-",min(r1,i),"=",minus
      Disp "O inverso de ",minus," é ",r2,"logo:"
      Disp r2,"+",minus,"=",plus
      Disp ""
    EndIf
  EndFor
EndFunc

I guess something like that should work, its just that i never worked with functions before...

Looking at the output, it seems that the answer to that problem is that all 3 digit numbers (starting from 100, since for example 012 is not valid as is actually a 2 digit number) minus the ternaries composed of: palindrome-1, palindrome, palindrome+1, will give an output of 1089.

So, the first palindrome is 101. That means that 100, 101 & 102 are excluded, then the second palindrome which is 111 means that 110, 111 & 112 are out, and so on until you get to 999 which excludes 998 & 999, since 1000 is a 4 digit number...

In summary there are 3 cases:
* If number is palindrome, answer = 0
* If number is palindrome +/- 1, answer = 198
* else, answer = 1089

Quote from: joao9856 on November 15, 2012, 06:11:51 pm

I guess something like that should work, its just that i never worked with functions before...

It's really simple :) A program just runs and then terminates. You can't do anything with it so to say. Functions however return a value. So say you have the following situation:

Code: [Select]

Define main()=
Prgm
    a=3
    b=4
    c=a+b
EndPrgm

Code: [Select]

Define main()=
Func
    a=3
    b=4
    c=a+b
EndFunc

The program just does a+b and then stops. The function does a+b and returns the answer (7).

Not sure anymore if functions need a return or not?

Omnimaga

Calculator Community => TI Calculators => TI-BASIC => Topic started by: joao9856 on November 13, 2012, 01:17:45 pm