Yes, I think there is only one parameter. I got the same error.

You are probably not considering the order of the characters. If you can't put the strings on top of each other, like in the description, they are not considered a merge.

Good luck! :-)

Hi, I copy your code and run it, got Process was terminated. It took longer than 8000ms to complete. It's not about Should not modify the original array. It only means that your code is too slow. You need to optimize your code and make it run fast ;-)

I've read your code, it seems not modify the original array, perhaps the reason may be your code got a incorrect result at this test part(I am not sure, because I can not test your code now, I using a phone, only can browse web page but can not running code. I will test it when I using a computer ;-)

after running function, the original array should not be modified. please make sure you didn't use sort,splice,reverse,etc.. If you are surely that you didn't modify it, please paste your code here ;-)