- 0013_roman_to_integer
- 0014_longest_common_prefix
- 0020_valid_parentheses
- 0028_implement_strstr
- 0038_count_and_say
- 0058_length_of_last_word
- 0067_add_binary
- 0125_valid_palindrome
- 0344_reverse_string
- 0345_reverse_vowels_of_a_string
- 0383_ransom_note
- 0387_first_unique_character_in_a_string
- 0415_add_strings
- 0434_number_of_segments_in_a_string
- 0443_string_compression
- 0459_repeated_substring_pattern
- 0482_license_key_formatting
- 0520_detect_capital