Strings
Problems on strings, including searching for a substring, palindromes, anagrams, comparing and sorting strings, parsing and transforming text, counting characters and words, and string periods.
Narrower problem sets are under Prefix function, Z-function, Hashing and String suffix structures.
Problems
XML#3135
Medium
Clickomania#3136
Hard
Equation#3150
Easy
Regular expressions (Easy)#3181
Very easy
Pathological Paths#3198
Medium
Palindrome#3209
Very easy
Period#3345
Medium
Hidden Code#3382
Medium
Label#3514
Hard
Bracelets#3571
Easy
Digit-wise modulo 3#3651
Very easy
Without reciprocity#3654
Very easy