Step 1: Divide the number into separate digits:
42252 => 4 2 2 5 2
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
4 to 2 = 2
2 to 2 = 0
2 to 5 = 3
5 to 2 = 3
2 to 4 = 2
Step 3: Combine the filters to a string:
2 0 3 3 2 = 20332