the website doesn't verify the accuracy of sort output. it just gives you the first SO answer that a) has a code snippet b) which is error-free c) and has a f

the website doesn't verify the accuracy of sort output. it just gives you the first SO answer that a) has a code snippet b) which is error-free c) and has a function that can be extracted and run ...for your input format, and returns the output of passing your input code into it. It's true to the xkcd mission, which is just to find SO answers until it returns something, not to actually confirm it was sorted correctly.