A number is called 8-substring-friendly if every one of its digits belongs to a 8-substring. For example, 352114 is 8-substring-friendly, but 26(5)44 is not. For a given n, find T(n) the number of ...

In python, a String is a sequence of characters that may contain special characters or alphanumeric characters, for example, "we meet on Friday at 08:00 am". It is possible to access sub-parts of the ...

I believe it would be useful to do a tutorial on locating the position of a substring. Here is my youtube comment for reference: Is it possible to get the location of a substring within text in order ...