String Topic Wise Problem-Solving Questions
1. Basic String Operations
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | String Length | Easy | - | Link |
| 2 | String Copy | Easy | - | Link |
| 3 | String Concatenation | Easy | - | Link |
| 4 | String Compare | Easy | - | Link |
| 5 | String Reverse | Easy | - | Link |
| 6 | Palindrome Check | Easy | Link | Link |
| 7 | Substring Search | Easy | - | Link |
| 8 | String Tokenization | Easy | - | Link |
| 9 | Character Frequency | Easy | - | Link |
| 10 | Remove Duplicates | Easy | - | Link |
2. Two-Pointer Technique
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | Reverse String | Easy | Link | Link |
| 2 | Valid Palindrome | Easy | Link | Link |
| 3 | Remove Duplicates | Easy | Link | Link |
| 4 | Longest Substring Without Repeating Characters | Medium | Link | Link |
| 5 | Minimum Window Substring | Hard | Link | Link |
| 6 | Valid Palindrome II | Medium | Link | Link |
| 7 | Reverse Words in String | Medium | Link | Link |
| 8 | Backspace String Compare | Medium | Link | Link |
3. Sliding Window Technique
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | Longest Substring Without Repeating Characters | Medium | Link | Link |
| 2 | Minimum Window Substring | Hard | Link | Link |
| 3 | Longest Substring with At Most K Distinct Characters | Medium | Link | Link |
| 4 | Longest Repeating Character Replacement | Medium | Link | - |
| 5 | Permutation in String | Medium | Link | Link |
| 6 | Find All Anagrams in a String | Medium | Link | Link |
| 7 | Substring with Concatenation of All Words | Hard | Link | Link |
| 8 | Maximum Number of Vowels in a Substring | Medium | Link | - |
4. Pattern Matching
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | Implement strStr() | Easy | Link | Link |
| 2 | Regular Expression Matching | Hard | Link | Link |
| 3 | Wildcard Matching | Hard | Link | Link |
| 4 | Find and Replace Pattern | Medium | Link | Link |
| 5 | Word Pattern | Easy | Link | Link |
| 6 | Repeated Substring Pattern | Medium | Link | Link |
| 7 | KMP Algorithm | Medium | - | Link |
| 8 | Rabin-Karp Algorithm | Medium | - | Link |
5. String Manipulation
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | Reverse Words in String | Medium | Link | Link |
| 2 | Zigzag Conversion | Medium | Link | Link |
| 3 | Group Anagrams | Medium | Link | Link |
| 4 | Longest Common Prefix | Easy | Link | Link |
| 5 | String to Integer (atoi) | Medium | Link | Link |
| 6 | Integer to Roman | Medium | Link | Link |
| 7 | Roman to Integer | Easy | Link | Link |
| 8 | Count and Say | Medium | Link | Link |
6. Dynamic Programming on Strings
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | Longest Palindromic Substring | Medium | Link | Link |
| 2 | Longest Common Subsequence | Medium | Link | Link |
| 3 | Edit Distance | Hard | Link | Link |
| 4 | Distinct Subsequences | Hard | Link | Link |
| 5 | Interleaving String | Hard | Link | Link |
| 6 | Regular Expression Matching | Hard | Link | Link |
| 7 | Wildcard Matching | Hard | Link | Link |
| 8 | Scramble String | Hard | Link | Link |
7. String Hashing
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | Group Shifted Strings | Medium | Link | Link |
| 2 | Find All Anagrams in a String | Medium | Link | Link |
| 3 | Rabin-Karp Algorithm | Medium | - | Link |
| 4 | Count Distinct Substrings | Medium | - | Link |
| 5 | Longest Duplicate Substring | Hard | Link | Link |
| 6 | Palindrome Pairs | Hard | Link | Link |
8. String Compression
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | String Compression | Medium | Link | Link |
| 2 | Count and Say | Medium | Link | Link |
| 3 | Encode and Decode Strings | Medium | Link | - |
| 4 | Run-Length Encoding | Medium | - | Link |
| 5 | Huffman Coding | Hard | - | Link |
| 6 | LZW Compression | Hard | - | Link |
9. Advanced String Problems
| S.No | Problem Statement | Difficulty | LeetCode | GeeksforGeeks |
|---|---|---|---|---|
| 1 | Minimum Window Subsequence | Hard | Link | - |
| 2 | Shortest Palindrome | Hard | Link | Link |
| 3 | Longest Happy Prefix | Hard | Link | Link |
| 4 | Smallest Range Covering Elements from K Lists | Hard | Link | Link |
| 5 | Text Justification | Hard | Link | - |
| 6 | Minimum Remove to Make Valid Parentheses | Medium | Link | - |
| 7 | Longest Valid Parentheses | Hard | Link | Link |
| 8 | Minimum Number of Swaps to Make the String Balanced | Medium | Link | Link |
Related String Resources