Most Asked String LeetCode Questions in Google Interviews
String problems are a core part of Google software engineering interviews. These questions often test your ability to manipulate text efficiently and apply optimized approaches.
Many problems involve techniques like sliding window, hashing, and two pointers, making strings one of the most versatile topics in coding interviews.
In this guide, we have compiled some of the most frequently asked String problems reported in Google interviews. Each question includes its difficulty level, interview frequency, and a direct link to the LeetCode problem so that you can start practicing immediately.
Below is a curated list of String LeetCode questions asked in Google interviews.
| Sl.No | Question | Difficulty | Frequency | LeetCode Link |
|---|
| 1 | Longest Substring Without Repeating Characters | MEDIUM | 82.60% | Solve |
| 2 | Group Anagrams | MEDIUM | 78.90% | Solve |
| 3 | Valid Parentheses | EASY | 77.70% | Solve |
| 4 | Longest Palindromic Substring | MEDIUM | 77.10% | Solve |
| 5 | Merge Strings Alternately | EASY | 75.00% | Solve |
| 6 | Longest Common Prefix | EASY | 70.80% | Solve |
| 7 | Generate Parentheses | MEDIUM | 68.60% | Solve |
| 8 | Letter Combinations of a Phone Number | MEDIUM | 68.20% | Solve |
| 9 | Roman to Integer | EASY | 66.10% | Solve |
| 10 | Word Search | MEDIUM | 63.60% | Solve |
| 11 | Word Break | MEDIUM | 60.60% | Solve |
| 12 | Reverse Words in a String | MEDIUM | 59.50% | Solve |
| 13 | Valid Palindrome | EASY | 59.30% | Solve |
| 14 | Regular Expression Matching | HARD | 56.10% | Solve |
| 15 | Minimum Window Substring | HARD | 54.80% | Solve |
| 16 | Word Break II | HARD | 53.30% | Solve |
| 17 | Find the Index of the First Occurrence in a String | EASY | 52.80% | Solve |
| 18 | Zigzag Conversion | MEDIUM | 52.80% | Solve |
| 19 | Integer to Roman | MEDIUM | 52.20% | Solve |
| 20 | Rank Teams by Votes | MEDIUM | 51.60% | Solve |
| 21 | Valid Anagram | EASY | 51.40% | Solve |
| 22 | Move Pieces to Obtain a String | MEDIUM | 50.00% | Solve |
| 23 | Longest Valid Parentheses | HARD | 48.70% | Solve |
| 24 | String to Integer (atoi) | MEDIUM | 46.60% | Solve |
| 25 | String Transformation | HARD | 46.20% | Solve |
| 26 | Edit Distance | MEDIUM | 45.70% | Solve |
| 27 | Add Binary | EASY | 45.70% | Solve |
| 28 | Decode Ways | MEDIUM | 45.30% | Solve |
| 29 | Simplify Path | MEDIUM | 45.30% | Solve |
| 30 | Word Ladder | HARD | 44.80% | Solve |
| 31 | Length of Last Word | EASY | 43.20% | Solve |
| 32 | Isomorphic Strings | EASY | 43.10% | Solve |
| 33 | Wildcard Matching | HARD | 41.60% | Solve |
| 34 | Count and Say | MEDIUM | 40.40% | Solve |
| 35 | Expressive Words | MEDIUM | 39.80% | Solve |
| 36 | Shortest Palindrome | HARD | 38.00% | Solve |
| 37 | Number of Substrings Containing All Three Characters | MEDIUM | 37.90% | Solve |
| 38 | First Unique Character in a String | EASY | 37.90% | Solve |
| 39 | Multiply Strings | MEDIUM | 37.60% | Solve |
| 40 | Sentence Screen Fitting | MEDIUM | 37.50% | Solve |
| 41 | Lexicographically Smallest Beautiful String | HARD | 37.50% | Solve |
| 42 | Unique Length-3 Palindromic Subsequences | MEDIUM | 37.50% | Solve |
| 43 | Maximum Score After Splitting a String | EASY | 37.50% | Solve |
| 44 | Find Longest Special Substring That Occurs Thrice I | MEDIUM | 37.50% | Solve |
| 45 | Minimum Number of Operations to Move All Balls to Each Box | MEDIUM | 37.50% | Solve |
| 46 | Sender With Largest Word Count | MEDIUM | 37.50% | Solve |
| 47 | Valid Word Abbreviation | EASY | 37.50% | Solve |
| 48 | Text Justification | HARD | 36.90% | Solve |
| 49 | Group Shifted Strings | MEDIUM | 35.40% | Solve |
| 50 | Word Search II | HARD | 34.70% | Solve |
You can also track your progress and practice these questions using our tool:
Google LeetCode Interview Questions Tracker
How to Prepare for String Questions in Google Interviews
To perform well in Google coding interviews, it’s important to develop strong skills in string manipulation and pattern recognition.
Some useful preparation strategies include:
- Practicing sliding window techniques for substring problems
- Using hash maps for character frequency counting
- Solving problems involving palindromes and pattern matching
- Understanding two pointer approaches for string traversal
- Optimizing brute-force solutions using efficient string operations
Mastering string problems will significantly improve your problem-solving speed and coding confidence.
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