1. Implement a function to find the lexicographically smallest string that can be formed by removing any number of characters.
2. Write a function to find the minimal number of operations to convert one string to another using only insertions, deletions, and cyclic shifts.
3. Implement a function to find the longest palindrome subsequence that can be constructed from two given strings.
4. Write a function to check if a string is a valid transformation of another string by reversing all vowels in a cyclic manner.
5. Implement a function to find the minimal number of operations to convert a string into a palindrome, allowing both insertions and deletions.
6. Write a function to check if a string can be partitioned into k palindromic substrings.
7. Implement a function to find the minimal number of swaps to make a string into an anagram of another string.
8. Write a function to find the lexicographically smallest cyclic rotation of a string using a suffix array.
9. Implement a function to find the longest subsequence common to both a string and its reverse.
10. Write a function to check if a string can be segmented into words using a given dictionary, where words can overlap.
11. Implement a function to find the minimal number of operations to transform one string into another, allowing both substring reversals and replacements.
12. Write a function to find the smallest set of characters that need to be removed from a string to make it a palindrome.
13. Implement a function to find all possible minimal length palindromes that can be formed by rearranging a string.
14. Write a function to find the longest substring that can be made a palindrome by rearranging its characters.
15. Implement a function to find the minimal number of adjacent swaps to arrange the characters of a string in lexicographical order.
16. Write a function to find the lexicographically largest palindrome that can be formed from two strings by alternating their characters.
17. Implement a function to check if a string is a valid subsequence of another string when rotated.
18. Write a function to find the lexicographically largest subsequence of a string that contains all vowels in order.
19. Implement a function to find the minimal number of operations to transform one string into another, allowing only substring deletions.
20. Write a function to find the longest palindromic substring where the characters are in increasing order.
21. Implement a function to find the smallest subsequence of a string that contains all the distinct characters of another string.
22. Write a function to find the lexicographically smallest substring of a string that can be rearranged into a palindrome.
23. Implement a function to find the minimal number of operations to convert one string into another by only reversing substrings.
24. Write a function to find the longest common substring between two strings using dynamic programming and bitwise operations.
25. Implement a function to find the smallest number of operations to split a string into substrings where each substring is a palindrome.
26. Write a function to find the lexicographically smallest string that can be formed by deleting at most k characters.
27. Implement a function to check if two strings can be made identical by rotating their substrings.
28. Write a function to find the smallest palindrome that can be formed by inserting at most one character into a string.
29. Implement a function to find the longest substring of a string that is an anagram of another given string.
30. Write a function to find the lexicographically smallest sequence of swaps needed to transform one string into another.
31. Implement a function to find the minimal number of operations to transform a string into its reverse.
32. Write a function to find the longest substring that contains all distinct characters in reverse order.
33. Implement a function to check if a string can be transformed into a palindrome by rotating any substring.
34. Write a function to find the lexicographically smallest palindrome that can be formed from a string by deleting at most k characters.
35. Implement a function to find the minimal number of operations to transform one string into another, allowing both rotations and insertions.
36. Write a function to find the lexicographically largest string that can be formed by rearranging the characters of a string.
37. Implement a function to find the longest palindrome that can be formed by rearranging a string's characters.
38. Write a function to find the smallest number of adjacent swaps to make a string into a palindrome.
39. Implement a function to check if two strings can be made identical by rearranging any two non-overlapping substrings.
40. Write a function to find the longest substring of a string that is an anagram of another given string.