form four different numbers how can i find out the minimum and maximum which can created from tem, and how can I counted how many steps need to do to get the number 6574

a four-digit number in Matlab, the main thing that did not consist of the same numbers, then you need to have the program was of the digits of this number the maximum number and the minimum number (eg, 7465: Minimum-4567, the maximum-7654) and it is necessary, to programme counted how many of these steps need to do to get the number 6574

[Walter Roberson]

Once you have found the maximum and minimum, what do you do with that pair?

Whatever you do with that pair, is it certain that you will eventually reach 6574 ?

Is it permitted to have (for example) 1333 since not all of the digits are the same?