Not very difficult, indeed !

If you don’t mind about a final sort of your unique CJK characters, here is a way to achieve it, very quickly :-))

First of all, just backup your original list ( A safe behaviour to adopt, in any case ! )

Now, let suppose you have the following list of CJK characters. I just added, after a space, the Unicode code-point of each character

丰 4E30
不 4E0D
丆 4E06
与 4E0E
不 4E0D
丰 4E30
且 4E14
世 4E16
中 4E2D
且 4E14
与 4E0E
丰 4E30
丟 4E1F
中 4E2D
与 4E0E
中 4E2D
丆 4E06
丰 4E30

First, perform a classical sort, with the menu option Edit > Line Operations > Sort lines Lexicographically Ascending. We get, immediately, the sorted text, below :

丆 4E06
丆 4E06
不 4E0D
不 4E0D
与 4E0E
与 4E0E
与 4E0E
且 4E14
且 4E14
世 4E16
丟 4E1F
中 4E2D
中 4E2D
中 4E2D
丰 4E30
丰 4E30
丰 4E30
丰 4E30

Now :

• Move back to the very beginning of your file ( Ctrl + Origin )

• Open the Replace dialog ( Ctrl + H )

• In the Find what: zone, paste or type the regex (?-s)^(.+\R)\1+

• Leave the Replace with: zone EMPTY

• Select the Regular expression search mode

• Click on the Replace All button

=> You should get, only, the two lines, below :

世 4E16
丟 4E1F

Et voilà !! It just remains the two unique characters of the original list :-))

Notes :

• The first part (?-s) is a modifier which implies that any dot will match a single standard character and not EOL characters

• Then, the ^ symbol is a zero-length assertion, which means beginning of line

• Now, the part (.+\R) represents a non-empty range of consecutive standard characters, followed by its EOL character(s). As the current complete line is enclosed in parentheses, it’s stored as group 1

• Finally, the part \1+, is a repeated back-reference to group 1, which looks for any non-empty range of consecutive lines, identical to the first one !

• As the replacement zone is EMPTY, all these repeated lines ( > 1 ) are simply deleted !

Best Regards,

guy038