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50 Strings interview questions

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Basic String Concepts

1.
What is a String in Data Structures?
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2.
Compare Strings and Character Arrays.
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3.
What is a Null-Terminated String?
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4.
Explain Mutability and Immutability in the context of Strings.
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5.
How do different programming languages implement and manipulate Strings?
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String Properties and Operations

6.
Why are Character arrays preferred over Strings for passwords?
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7.
Discuss how indexing works in Strings and how it affects various operations.
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8.
What are Pascal Strings?
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9.
Explain how String Concatenation works and the time complexity associated with it.
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10.
Describe the Time Complexity of substring search in Strings.
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Advanced String Data Structures

11.
What is a Rope data structure?
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12.
Name key Advantages and Limitations of Ropes.
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13.
What are some Practical Applications of a Ropes?
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14.
Compare Ropes vs. StringBuilders.
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15.
Compare the performance of Strings vs. Ropes.
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String Searching Algorithms

16.
Explain the Boyer-Moore Algorithm.
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17.
Compare Knuth-Morris-Pratt, Boyer-Moore, and Rabin-Karp search algorithms.
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18.
Implement and discuss the complexity of the Z-algorithm for pattern searching.
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19.
How does the BNDM algorithm work for string matching?
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String Manipulation Challenges

20.
Check the String for Balanced Parentheses, using Linear Time and Constant Space.
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21.
Remove the Minimum Number of parentheses to make a String valid.
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22.
Reverse a String using Stack.
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23.
Solve the String Compression problem (e.g., “aaabccddd” to “a3b1c2d3”)?
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24.
Write an algorithm to find the Longest Palindromic Substring within a given string.
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String Pattern Problems

25.
Check if a String is a Palindrome.
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26.
Find all Permutations of a String.
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27.
Check if two Strings are Anagrams.
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28.
Find the Longest Repeating Subsequence in a String.
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29.
Implement a solution to find the Shortest Palindrome that can be formed by adding characters to the beginning of a given string.
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Reversal and Transformation

30.
Reverse the ordering of words in a String.
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31.
Write a function to Reverse each word in a sentence while preserving whitespace and initial word order.
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32.
Transform one string to another using a minimal number of append/delete operations.
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33.
Implement an in-place algorithm to Reverse a String without using additional buffer space.
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String Comparison and Sorting

34.
Explain why String Sorting differs from sorting other types of data and how to optimize it.
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35.
Discuss the Longest Common Prefix algorithm and its applications.
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36.
Implement a solution for Grouping Anagrams given an array of strings.
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37.
How do you compare version numbers represented as strings?
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Encoding and Encryption String Problems

38.
Describe how you would Encode and Decode a string using the Run-Length Encoding algorithm.
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39.
Implement a simple String Encryption method such as Caesar Cipher and discuss its security.
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40.
Explain the challenges of Unicode Encoding and Decoding in strings and how programming languages address these issues.
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Regular Expressions and Pattern Matching

41.
How are Regular Expressions used for string pattern matching and validation?
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42.
Write a regular expression to validate email addresses.
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43.
Implement a regex matcher to check if a string conforms to a given pattern.
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Multilingual and Locale-Specific Issues

44.
Discuss how strings are handled in a Multilingual Context and the implications for data storage and manipulation.
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45.
Explain the concept of Locale-Specific Sorting and how it can affect string comparison algorithms.
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Memory Efficient String Processing

46.
How can you minimize memory usage when manipulating large strings?
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47.
Discuss the use of Flyweight Pattern for memory-efficient string storage.
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String Data Structures Interview Challenges

48.
Detect if a string has any duplicate characters without using additional data structures.
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49.
Check for an Isomorphic String relationship between two given strings.
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50.
Implement a string tokenizer that can split a string into tokens based on different delimiters.
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