I agree this is best as a series of small articles.
Some of my favorite techniques:
1) Use a tally table and SUBSTRING() to represent character string as a table of individual characters. Great for filtering out unwanted characters.
2) Finding gaps/islands in series of numbers.
3) Determining whether two strings are alike except for a typo (1 character different, omitted, added or transposed).
I'll volunteer to do any of the above.
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