Description: Given a String s, a sub-string is defined as a non-empty string that can be obtained by applying following operation
- Remove zero or 1 character from left side of s
- Remove zero or 1 character from right side of s
- Remove zero or 1 character from left & right side of s
Find how many distinct sub-string possible.
Characters in string are [a-z]
String length can be up to 10^5