1432. Max Difference You Can Get From Changing an Integer

You are given an integer num. You will apply the following steps to num two separate times: - Pick a digit x (0 <= x <= 9). - Pick another digit y (0 <= y <= 9). Note y can be equal to x. - Replace all the occurrences of x in the decimal representation of num by y. Let a and b be the two results from applying the operation to num independently. Return the max difference between a and b. Note