Step 1: Divide the number into separate digits:
93488 => 9 3 4 8 8
Step 2: Calculate the distance between each digit and the next (the last digit with the first):
9 to 3 => 6
3 to 4 => 1
4 to 8 => 4
8 to 8 => 0
8 to 9 => 1
Step 3: Convert distances to codes (0=E[qual],
1 & 9 = C[onsecutive], 2-8 = N[one]):
6 => N
1 => C
4 => N
0 => E
1 => C
Step 4: Combine the filters to a string:
N C N E C = NCNEC