Guess the number

This is a very simple number guessing game.

Some hidden n digits of unique numbers will be generated at the beginning. Each digit could have a value of 0-9. The goals is to guess all the hidden digits and their correct positions.

Everytime a guess is made, there will be a response of x and y.
x denotes how many digits are guessed correctly.
y denotes how many correct digits are in the correct position. The game is won when x equals y equals n.

Guess the number is a mind game that will test your ingenuity. It is more difficult than a simple puzzle and you can increase its difficulty even more by adding more digits (the minimum is 4 and the maximum 8).