Step 1: Divide the number into separate digits:
0034 => 0 0 3 4
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
0 to 0 = 0
0 to 3 = 3
3 to 4 = 1
4 to 0 = 4
Step 3: Combine the filters to a string:
0 3 1 4 = 0314