Step 1: Divide the number into separate digits:
11018 => 1 1 0 1 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
1 to 1 = 0
1 to 0 = 1
0 to 1 = 1
1 to 8 = 7
8 to 1 = 7
Step 3: Combine the filters to a string:
0 1 1 7 7 = 01177