Top 50 Problems on Hash Data Structure asked in SDE Interviews Last Updated : 03 Jul, 2023 Comments Improve Suggest changes Like Article Like Report Hashing is a technique or process of mapping keys, and values into the hash table by using a hash function. It is done for faster access to elements. The efficiency of mapping depends on the efficiency of the hash function used. To learn more about hashing and hashmaps, please refer to the Tutorial on Hashing. Given below are the most frequently asked interview questions on Hash:Easy Level Problems on Hash Data Structure Find whether an array is a subset of another arrayFind the frequency of each character in a stringFind the first non-repeating character in a stringFind the intersection of two arraysFind missing elements of a rangeFind the pair with given sum in an arrayFind the count of distinct elements in an arrayCount number of Distinct Substring in a StringPrint all distinct words from a paragraphCount all distinct pairs with difference equal to kRemove minimum number of elements such that no common element exist in both arrayMinimum insertions to form a palindrome with permutations allowedFind the only repetitive element between 1 to n-1Remove duplicates from an arrayMedium Level Problems on Hash Data Structure Find the length of the longest consecutive sequence in an arrayFind all pairs with a given sum in an arrayLongest Consecutive SubsequenceFind the first repeating element in an arrayFind the majority element in an arrayFind the subarray with given sum in an arrayGroup all anagrams in an array of stringsLongest sub-array having sum kMaximum length subarray with equal number of 0s and 1sPrint all subarrays with 0 sumSort an array according to the order defined by another arrayRange Queries for Frequencies of array elementsCount subarrays having total distinct elements same as original arrayAll unique triplets that sum up to a given valueSmallest subarray with k distinct numbersMaximum possible difference of two subsets of an arrayFind the length of largest subarray with 0 sumFind Itinerary from a given list of ticketsFind all pairs (a, b) in an array such that a % b = kCount the number of subarrays having a given XORHard Level Problems on Hash Data Structure Top k numbers in a streamTransform One String to Another using Minimum Number of Given OperationFind the longest substring with k unique charactersFind the minimum window in a string containing all characters of another stringImplement LRU CacheLongest subarray with sum divisible by kCount distinct elements in every window of size kCheck if an array can be divided into pairs whose sum is divisible by kClone a Binary Tree with Random PointersSmallest window in a string containing all the characters of another stringLength of longest strict bitonic subsequenceCount maximum points on same linePhone directoryFind number of Employees Under every ManagerPalindrome Substring QueriesFind All Duplicate Subtrees Comment More infoAdvertise with us Next Article Commonly Asked Data Structure Interview Questions R RishabhPrabhu Follow Improve Article Tags : Hash DSA top-dsa-problems Practice Tags : Hash Similar Reads Commonly Asked Data Structure Interview Questions on Hashing Hashing is a technique to map data to fixed-size values using a hash function, often used for quick lookups, insertions, and deletions in applications like databases and caches. The core concept behind hashing is to map large data to smaller fixed-size values, typically integers, through a hash func 4 min read Commonly Asked Data Structure Interview Questions on Hashing Hashing is a technique to map data to fixed-size values using a hash function, often used for quick lookups, insertions, and deletions in applications like databases and caches. The core concept behind hashing is to map large data to smaller fixed-size values, typically integers, through a hash func 4 min read Top 20 Hashing Technique based Interview Questions Hashing is a powerful technique in Data Structures and Algorithms (DSA) that involves mapping data to a fixed-size value using a hash function. The key advantage of hashing is its ability to provide fast lookups, often achieving constant time complexity, O(1), for operations like searching and inser 1 min read Commonly Asked Data Structure Interview Questions To excel in a Data Structure interview, a strong grasp of fundamental concepts is crucial. Data structures provide efficient ways to store, organize, and manipulate data, making them essential for solving complex problems in software development.Interviewers often test candidates on various data str 6 min read Commonly Asked Data Structure Interview Questions To excel in a Data Structure interview, a strong grasp of fundamental concepts is crucial. Data structures provide efficient ways to store, organize, and manipulate data, making them essential for solving complex problems in software development.Interviewers often test candidates on various data str 6 min read Commonly Asked Data Structure Interview Questions To excel in a Data Structure interview, a strong grasp of fundamental concepts is crucial. Data structures provide efficient ways to store, organize, and manipulate data, making them essential for solving complex problems in software development.Interviewers often test candidates on various data str 6 min read Like