This can only work in your local environment where GMP has been installed.

same here

It took me a while, but now I understand, if in the expression there is a 1 already, it can't be 1 because if it were one, there would be no ? to decipher.

OMG, thank you so much.

What language? issue not clear, OP can reraise one if he encounters the issue (in a more specific manner)

The input numbers are so high it turns the answer to a scientific notation in JavaScript. You can easily convert scientific notation to normal only up to e+20. So you have to come up with an algorithm to sum these numbers in another way.

No, read what I copied/pasted there. If 1 is already in the expression then it can't be the unknown digit.

1 supposed to work since 1 * 11 = 11

All of the ?s in an expression will represent the same digit (0-9), and it won't be one of the other given digits in the expression.

^ That

1*11=11, why do you say 1 does not work here? The lowest solution is 1, but it wants 2.

Thanks so much! I'll dive back in and implement some fixes

There are two mistakes in your code; the first one is that you can't sort something empty, hence you should add a check whether the string is null at the beginning; the second is that your list (sorted) is outside your function, therefore it doesn't reset itself and lead to several errors, you must re-init it at the beginning of your function.

Have a nice day :)

donaldsebleung or stɛffan153: could you fix the swap of actual and expected in PHP translation?

Just encountered an issue with test #3 + #4 in PHP,
it expects "pncakes" which is wrong, it should be expecting "pancakes"