32 problems
| Name | Difficulty |
|---|---|
| Count Vowels in a String | Very Easy |
| Hello World String | Very Easy |
| Reverse a String | Very Easy |
| Valid Palindrome | Easy |
| Valid Parentheses | Easy |
| Valid Anagram | Easy |
| 24-Hour to 12-Hour Time Conversion | Easy |
| Fizz Buzz | Easy |
| Longest Palindromic Substring | Easy |
| Hexadecimal to Decimal Conversion | Easy |
| 12-Hour to 24-Hour Time Conversion | Easy |
| Password Validation | Easy |
| Word Break | Medium |
| Word Ladder | Medium |
| Word Search - Find word | Medium |
| Implement Trie (Prefix Tree) | Medium |
| Decode Ways | Medium |
| Caesar Cipher | Medium |
| Reverse Words in a String | Medium |
| Decompress Encoded String | Medium |
| Longest Substring Without Repeating Characters | Medium |
| String Compression | Medium |
| Top K Frequent Words | Medium |
| String Rotation Checker | Medium |
| Flip Coins Until All Heads | Medium |
| Decimal to Hexadecimal Conversion | Medium |
| Generate Parentheses | Medium |
| Generate Parentheses | Medium |
| Word Search - Find all words | Hard |
| Letter Combinations of a Phone Number | Hard |
| File Name Matching with Wildcards | Hard |
| Edit Distance | Hard |