Last Updated: 15 Mar, 2026
Top String Coding Interview Questions
String coding questions are a popular topic in many interviews. String interview questions range from smooth string manipulation questions to more complex issues like string matching algorithms and regular expressions. Go through this guide to excel in string coding interview questions. This guide will be useful in building your proficiency in solving string-based problems.
Difficulty
Companies
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Hot topics
Backtracking
Binary Search
Breadth-first Search
Dynamic Programming
Greedy
Hash Table
Heap
Math
Number Theory
Ordered Map
Recursion
Sorting
Stacks & Queues
Strings
Two Pointers
Categories
Problem Title
Exp
Difficulty
Avg. time
Attempted
Upvotes
80
Moderate
20 mins
7.4k
114
80
Moderate
30 mins
46k
166
40
Easy
15 mins
2.8k
68
40
Easy
10 mins
84.5k
454
120
Hard
50 mins
51k
272
80
Moderate
20 mins
8.5k
77
80
Moderate
20 mins
16.4k
154
40
Easy
10 mins
97k
434
80
Moderate
25 mins
11.7k
71
120
Hard
45 mins
23k
92
120
Hard
40 mins
24.8k
89
40
Easy
15 mins
7.2k
71
80
Moderate
25 mins
4.4k
12
40
Easy
15 mins
16.7k
78
40
Easy
10 mins
2.7k
17
80
Moderate
35 mins
7.2k
58
80
Moderate
15 mins
1.8k
8
80
Moderate
35 mins
6.9k
45
80
Moderate
30 mins
23k
146
80
Moderate
-
1.6k
8
80
Moderate
15 mins
2.6k
36
40
Easy
10 mins
9.4k
67
80
Moderate
-
12k
56
80
Moderate
10 mins
2.3k
22
120
Hard
35 mins
2.2k
23
1
2
3
Frequently Asked Questions
How to solve a string coding interview question?
Practice is the key. Upon solving a number of string coding questions, you will realize that there are a few standard techniques to solve string-based coding questions. Like two pointers, sliding window, string permutations, thinking along the lines of map container, inversion number, greedy approach, etc.
How hard are string coding interview questions?
It is a general trend in MAANG companies to ask moderate to hard level string-based coding questions. However, practicing a lot of already-asked string-based coding questions can help in your final interview. If you know the approaches that can be applied beforehand, you will be in a better position at your interview.
How to approach string coding questions?
String coding questions can be broadly divided into 5 categories. Validate the input string -> greedy Search a substring satisfying certain criteria -> Two pointers Search the largest substring satisfying a criteria -> Sliding window String permutations -> backtracking DP Now, you can categorise the problem into one of the above-mentioned categories and solve accordingly.
What is the best way to answer string coding interview questions?
Firstly, understand the problem properly and give a few examples to the interviewer. Then, think about the ways that can be used to solve the problem. If you get stuck on an approach, be flexible enough to change it accordingly. Finally, explain the approach to the interviewer and code the solution.