how the heck do they need more 2 letters to depict 120 elements, well i guess thats happens when you let non CS guys name things.

lul, cant figure it out ?

are complex powers alowed ?

like 5^(52-51)

this is c#, get rekt btw

there is tiny bit of issue on the c# version.
in one of the last tests where the answer should be -12042.760875
my implementation shows that there it is -12042.760875002
i think it is just because the test program used to validate has limited precision on the 6th decimal

'?*11=??'

the above expression is validated by 1 and 0 but the test requires you put a 2
c#

it doesnt look like it, but its very efficient compared to what i see as top answers if not the most efficient solution of them all.

it hardcodes the max number of possible coins tho, so thats a minus

it is a long piece of code but it can expand and scale very nicely case romans cared to count things over 9999, as it only keeps a list of their numerals.
unlike the top rated solutions where they just keep every possible outcome in arrays beforehand.

turns out numbers where limited to 0-9 , but i made it to work on any kind of number, so hey, its longer than the rest but its adaptable.