GeeksforGeeks

Commonly Asked Data Structure Interview Questions on Strings

Last Updated: 23 July 2025

Strings are essential data structures used to represent sequences of characters and are frequently encountered in coding interviews. Questions often focus on string manipu...read more

Python String Coding Practice Problems

Last Updated: 23 July 2025

This collection of Python string coding practice problems is designed to help you learn string manipulation.The following links contain coding problems where you need logi...read more

Strings

Python

Python string-programs

Check for Binary String

Last Updated: 23 November 2024

Given a string s, the task is to check if it is a binary string or not. A binary string is a string which only contains the characters '0' and '1'.Examples:Input: s = "010...read more

Strings

DSA

strings

Longest Common Prefix using Sorting

Last Updated: 23 July 2025

Given an array of stringsarr[],the task is to return thelongest common prefixamong each and every strings present in the array. If there’s no prefix common in all the stri...read more

Longest Common Prefix

String Problems Topic Wise

Last Updated: 23 July 2025

In this post, string problems based on different topics are mentioned. Please refer String Data Structure article for fundamentals, basic operations and problems based on ...read more

Strings

DSA

Program to Search a Character in a String

Last Updated: 25 March 2025

Given a character ch and a string s, the task is to find the index of the first occurrence of the character in the string. If the character is not present in the string, r...read more

Strings

DSA

Find a word with highest number of repeating characters

Last Updated: 08 January 2025

Given a string which contains multiple words, our task is to find the word which has highest number of repeating characters.Examples:Input: str = "hello world programming"...read more

Strings

Hash

DSA

String Subsequence and Substring in Python

Last Updated: 23 July 2025

Subsequence and Substring both are parts of the given String with some differences between them. Both of them are made using the characters in the given String only. The d...read more

Special Ranking Teams by Votes

Last Updated: 23 July 2025

Given an array of strings votes[], representing the voters' rankings. A special ranking system where each voter ranks all teams from highest to lowest. The task is to Sort...read more

Count number of times given sentence can be fitted on screen

Last Updated: 11 June 2024

Given a screen with dimensions rows*cols, and a sentence represented as a list of strings. The task is to return the number of times the given sentence can be fitted on th...read more

two-pointer-algorithm

Interview-Questions

Remove at most K letter to equalize the frequency

Last Updated: 11 June 2024

Given a string S of length n, consisting of lowercase English letters. The task is to check if it is possible to remove at most K letter from S such that the frequency of ...read more

Find First Palindromic String in Array

Last Updated: 11 June 2024

Given an array of strings arr, the task is to return the first palindromic string in the array. If there is no such string, return an empty string "".Example:Input: arr = ...read more

Find Longest Palindromic Subsequence II

Last Updated: 23 July 2025

Given a string s, return the length of the longest good palindromic subsequence in s such that:It has an even length.No two consecutive characters are equal, except the tw...read more

Find Repeated DNA Sequences

Last Updated: 10 June 2024

Given a string S which represents DNA sequence, the task is to find all the 10-letter long substring that are repeated more than once. Returning the sequence can be done i...read more

Count K-Length Substrings With No Repeated Characters

Last Updated: 11 October 2024

Given a string S and an integer k, the task is to return the number of substrings in S of length k with no repeated characters.Example:Input: S = "geeksforgeeks", k = 5Out...read more