> Ever try or even see a "Leet-Code" style question that stated the problem without providing example results? [...] How do you ever know you got the correct result? You don't. Perhaps worse, you are confident in a "solution" that includes an "off by 1" bug.
Yes. Well, no--even worse. When I took intro CS in college many years ago we were given a problem with incorrect example results due to an off-by-one error in the code written by a TA. After many hours of banging my head against the desk and eventually working several cases out by hand on paper, I pointed this out to the professor. Rather than correct the error he emailed the class that the example results were only intended to demonstrate the formatting of the input and output, and should not be relied on to be correct.