Write a function that is a number guessing game. It should determine a random number from 1-100, and let the user guess the number. It should report back whether their guess is correct, too high, or too low. Important: if the user guesses a number they've already guessed, it should tell them they have previously guessed this number. Until they guess the correct number, it should continue to prompt them. Once they've guessed the correct number, it should congratulate them and tell them how many guesses they took to solve the problem (minus any duplicate guesses).