Let be an ascending sequence of number. If swapping the and position is considered as one step for , then determine the least number of steps needed to reorder the sequence to be a descending one (). How can you be sure that your number is indeed the least number of steps?
P.S. Even though this problem looks like a toy problem, it definitely isn’t. This is a dumbing down version of a real problem I’ve solved in using a computer program before. I really saved a lot of time by solving this problem 😀