HP 50g graphing calculator - how to detect duplicate values while entering INFORM input repeatedly

[JKova]

Hi dear HP Community , 

Before i went to topic i hope that you'll safe and sound.

So here is my issue ,

I want to write a code which will able to detect duplicate values ( and show a message when value is detected as duplicate ( or multiple ) ) when repeatedly entering those values as INFORM input

Also i want to store all entered values in list and when  happens that some of entered values turns out to be duplicate ( or multiple ) I want to RE-ENTER that value , or these values if i have more of this  ,  and store it in place ( in list ) where that duplicate value was initially. 

So right above  is definition of my task , hope you understand what I'm asking. 

Also I'm referring to write this code for HP 50g graphing calculator and if possible in User RPL language.

Here is a code , "bug" code of what I done so far but unfortunately something is not wrong with my code.

source code of my attempt

Try this code on yourself !!

Problem with this code is in fact  when you entered multiple values , like as example 1, 1, 1 , 1 in INFORM input the value 

which is entered as second ( 2. nd )  will be recognized as duplicate but when you hit that number 1 at third ( 3.rd ) time  then value does not be recognized as duplicate. Again when you enter same number ( 1 ) ( or string but does not work on any string ) then you'll get a message which signalize a duplicate... so...  not so good algorithm.

Also my program does not works on any strings  and that is a bug too because i want to recognize duplicate in quite sort of data types including numbers , strings and global variable name NOT only numbers !!

Please help me with this i need this for my program !! 

Bye 🤗