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HashMap

A HashMap is a data structure that can map specific keys to certain values. The keys and values could be anything. Hashmaps can retrieve data faster than arrays and linked lists. A hashmap can check the presence of a particular key in O(1) time.

Introduction to Hashing

● Published Apr, 2022

In this blog, we will discuss the fundamentals of hashing and how it helps make our operations fast....Keep reading ...

Hash Functions In Data Structure

By Lokesh Sharma

● Published Feb, 2023

In this article, you are going to learn about hash functions in data structure. You will understand hashing and its types in detail....Keep reading ...

By Vivek Kumar Mehta

● Published Jan, 2022

Index mapping is the most widely used hashing technique. This blog will discuss the concept of index mapping as well as its implementation....Keep reading ...

By Ishita Chawla

● Published Oct, 2021

The following blog discusses double hashing along with its advantages and limitations of its implementation in C++....Keep reading ...

Rehashing in Data Structure

● Published Oct, 2021

Hashing is one of the favorite topics of interviewers when it comes to coding interviews, and in this blog, we will see the most frequently asked topic from hashing, i.e., load factor and rehashing....Keep reading ...

● Published Jun, 2022

In this blog, we will learn about Cuckoo Hashing which helps to achieve constant time worst-case complexity for lookups....Keep reading ...

Internal Working of HashMap in Java

● Published Oct, 2021

This article discusses Hash Maps in Java along with some Hashing Functions and their implementation to create a custom Hash Map....Keep reading ...

Hash Table vs STL Map

By brainstorming

● Published Jan, 2022

In this article, we will learn the difference between the hash map and the STL map. ...Keep reading ...

Difference between HashMap and Hash Table in Java

By Aditya Narayan Joardar

● Published Jan, 2022

This article discusses the difference between HashMap and Hash Table in Java....Keep reading ...

Difference between HashMap and TreeMap

● Published Oct, 2022

This article covers the difference between hashmap and treemap. The major difference between hashmap and treemap is hashmap implements the map interface, whereas treemap implements the sortedmap interface....Keep reading ...

What is the Difference Between HashSet and TreeSet?

By Gunjan Batra

● Published Oct, 2022

In this blog, we will study HashSet vs TreeSet. We will learn the difference between the two sets. ...Keep reading ...

Difference Between Hashmap And Linkedhashmap

● Published Oct, 2022

This article covers the difference between hashMap and linkedHashMap. The major difference between hashmap and linkedHashMap is hashmap implements the map interface, whereas treemap implements the hashMap interface. ...Keep reading ...

Separate Chaining and Open Addressing for Collision Handling

By Pranav Gautam

● Published Jan, 2022

Learn about the various Collision Handling mechanisms used in hashing techniques with interesting explanations and fun examples....Keep reading ...

Binary Subarrays with Sum

● Published Feb, 2022

In this blog, we will discuss a Leetcode Medium problem namely, Binary subarrays with sum along with its implementation in C++ language. ...Keep reading ...

LRU Cache Implementation

By vaishnavi pandey

● Published Oct, 2021

In this article, we’ll be seeing the implementation of the LRU cache in Java along with its working....Keep reading ...

Asteroid Collision

By Rasha Abdul Khader

● Published Oct, 2021

In this blog, we will discuss an interview question called Asteroid Collision with its approach and algorithm in detail....Keep reading ...

Reduce Array Size to The Half

By Soumya Agrawal

● Published Nov, 2021

The blog discusses in detail the Reduce Array Size to the Half Problem. We’ll discuss some approaches to solve the problem and the time and space complexity for each method....Keep reading ...

Check if there is a subarray with 0 sum

By Amarjeet Kumar

● Published Jul, 2022

This article will help you solve the famous interview question ‘Check if there is a subarray with 0 sum’...Keep reading ...

Check for palindrome after every character replacement query

By Amarjeet Kumar

● Published Jun, 2022

This article will help you solve the famous interview question, "Check for palindrome after every character replacement query"....Keep reading ...

Sum of all Unique Sub-array Sum for a Given Array

By Naman Kukreja

● Published Jun, 2022

In this blog, we will discuss the problem of finding sum of all unique sub-array sum for a given array....Keep reading ...

Count of Subarrays with Equal Number of 1’s and 0’s

● Published Jun, 2022

In this blog, we will learn a programming question based on hashing and subarray along with its time and space complexity. ...Keep reading ...

Elements to be added such that all elements of a range are present in an array

● Published Jun, 2022

In this article, we will discuss the solution for the given problem which is Elements to be added so that all the elements of a range are present. ...Keep reading ...

Longest Subarray Having Count of 1’s One More Than Count of 0’s

● Published Jun, 2022

In this blog, we will learn a programming question based on hashing and subarray, along with its time and space complexity....Keep reading ...

Subarrays with same Even and Odd elements

● Published Oct, 2022

In this blog, we are going to discuss a coding problem in which we have to print the count of even-odd subarrays in an array....Keep reading ...

Count all Subarrays having Sum Divisible by K

● Published Oct, 2022

In this blog, we will be discussing a coding problem in which we have to print the total count of all the sub-arrays that have a sum divisible by K....Keep reading ...

Minimum Operations to Choose Array Elements with Sum as K by Choosing an Element from the Front, or Rear or Both

● Published Dec, 2021

This article will brief you on the problem to calculate Minimum operations to choose Array elements with sum as K by choosing an element from the front, or rear or both ...Keep reading ...

Minimum Index Sum for the Common Elements of Two Lists

● Published Jul, 2022

In this article, we will discuss the Minimum Index Sum for Common Elements of Two Lists problem, including the algorithm and the implementation using hashmap in different languages. ...Keep reading ...

The Maximum possible difference of the sum of two subsets of an array

By Dhruv Sharma

● Published Jul, 2022

In this blog, we have discussed a question based on subsets of arrays that includes an essential concept from the topic, which we will explore through the explanation and the solutions and algorithms....Keep reading ...

Difference Between Concurrent Hashmap Vs Synchronized Hashmap

By dhananjay kumar

● Published Oct, 2022

This article incorporates information about the difference between concurrent hashmap and synchronized hashmap....Keep reading ...

Maximum Difference Between the First and Last Indexes of an Element in an Array

● Published Jul, 2022

In this blog, we will learn a programming question based on hashing, along with its time and space complexity. ...Keep reading ...

Maximum distance between two occurrences of same element in array

● Published Jul, 2022

In this article, we will see the solution Maximum distance between two occurrences of same element in array....Keep reading ...

Maximum Consecutive Numbers present in an Array

By Abhishek Nayak

● Published Oct, 2022

In this blog, we will discuss the approach using which we can find the count of maximum consecutive numbers present in an array....Keep reading ...

Find number of pairs in an array such that their XOR is 0

By Manan Singhal

● Published Jun, 2022

In this article, we will find number of pairs in an array such that their XOR is 0....Keep reading ...

Find the Highest Frequency of Non-Negative Powers that are the Same as Indices of Elements in the given Array

● Published Dec, 2021

In this article, we will learn how to find the frequency of the power which occurs highest times if we write the number present at an index of an array as some power of that index....Keep reading ...

Check if array contains contiguous integers with duplicates allowed

By Manan Singhal

● Published Jun, 2022

In this article, we will check if array contains contiguous integers with duplicates allowed....Keep reading ...

Sum of f(a[i], a[j]) over all pairs in an array of n integers

By Manan Singhal

● Published Jun, 2022

In this article, we will find the sum of f(a[i], a[j]) over all pairs in an array of n integers....Keep reading ...

Second most repeated word in a sequence

By devika varshney

● Published Jul, 2022

We will discuss the problem statement to find the second most repeated word in a sequence using the hashing method, including the algorithm, code, and complexities in this blog....Keep reading ...

Distribute items such that a person cannot take more than two items of the same type

By Indrajit Kumar

● Published Jun, 2022

This article gives you an in-depth solution to the question Distribute items such that a person cannot take more than two items of the same type....Keep reading ...

Distribute the Maximum Number of Chocolates Amongst X Students

● Published Jun, 2022

In this blog, we will learn how to solve the problem to distribute the maximum number of chocolates amongst X students via Hashing method. ...Keep reading ...

Difference between highest and least frequencies in an array

By Dhruv Sharma

● Published Jul, 2022

In this blog, we have discussed a question based on tracking the counts of the frequencies of the different elements in an array that includes an essential concept from the topic, which we will explore through the explanation and the solutions and al...Keep reading ...

Count subsets having distinct even numbers

By Indrajit Kumar

● Published Jun, 2022

We will discuss how to solve a question related to subset and array. ...Keep reading ...

The K Weakest Rows in a Matrix

By brainstorming

● Published Dec, 2021

The following article discusses the problem 'The K Weakest Rows in a Matrix' along with its solution and its implementation. ...Keep reading ...

Length of the largest subarray with 0 sum

By Indrajit Kumar

● Published Jun, 2022

We will discuss how to solve a question related to the subarray sum....Keep reading ...

Find All Pairs (a, b) In An Array Such That a % b = k

By devika varshney

● Published Jun, 2022

In this blog, we will discuss the problem statement to find all pairs (a, b) in an array such that a % b = k using hashing method, including the algorithm, code, and its complexities....Keep reading ...

Convert an array to reduced form(using hashtable)

By dhananjay kumar

● Published Jul, 2022

This article incorporates the implementation of converting an array into a reduced form using the hashtable....Keep reading ...

Count the Triplets

● Published Nov, 2021

This article covers the approach and implementation of the problem Count the Triplets in C++....Keep reading ...

Longest Subarray not having more than K Distinct Elements

By Teesha Goyal

● Published Jun, 2022

This article will discuss the problem of finding the longest subarray not having more than K Distinct Elements. We will also discuss the implementation and complexities of the solution to the problem....Keep reading ...

Find four elements that sum to a given value

By Amarjeet Kumar

● Published Jun, 2022

This article will help you solve the famous interview question, "Find four elements that sum to a given value"....Keep reading ...

Find all permuted rows of a given row in a matrix

By dhananjay kumar

● Published Jul, 2022

This article incorporates the implementation of finding all permuted rows of a given row in a matrix with the help of a hashset....Keep reading ...

Most frequent element in an array

By Anuradha_8356

● Published Jul, 2022

This article discusses a program to find the element that occurs the most frequently in the n-element size array Arry[]....Keep reading ...

Kth Distinct String in an Array

By Saksham Gupta

● Published Jan, 2022

In this blog, we will discuss one of the beginner-level problems asked on the topic of Hashmap, i.e., Kth Distinct String in an Array ...Keep reading ...

Check if an Array can be Divided into Pairs Whose Sum is Divisible by K

By Ayushi Goyal

● Published Jul, 2022

In this blog, we discuss how to check if an array can be divided into pairs whose sum is divisible by k, its algorithm, and implementation using a hashmap. ...Keep reading ...

Check if a given array contains duplicate elements within k distance from each other

● Published Jul, 2022

In this article, we will see the solution to an array problem that Check if a given array contains duplicate elements within k distance from each other. ...Keep reading ...

Find Three Element from Different Three Arrays such that A + B + C = Sum

By Ayushi Goyal

● Published Jul, 2022

In this blog, we discuss how to find three elements from different three arrays such that a + b + c = sum, its algorithm and implementation using a hashmap....Keep reading ...

Find Pairs of Positive and Negative Values Present in a Given Array

By Aditya kumar

● Published Jul, 2022

In this article, we will solve a very common problem to find pairs of positive and negative values present in a given array....Keep reading ...

Find pair with greatest product in array

● Published Jul, 2022

This article incorporates the implementation of the problem Find Pair with greatest product in array using hashing. ...Keep reading ...

First element occurring k times in an array

By dhananjay kumar

● Published Jul, 2022

This article incorporates the implementation of finding the first element that occurs k times in an array with the help of a hashmap...Keep reading ...

Non-overlapping sum of two sets

● Published Jul, 2022

We will discuss how to solve a question related to the hashing, called the non-overlapping sum of two sets....Keep reading ...

Numbers with prime frequencies greater than or equal to k

By Gaurav Bashisht

● Published Jul, 2022

In this article we will see how to solve ”Numbers with Prime frequencies greater than or equal to k.” with the help of its example, algorithm, explanation, code implementation and complexity analysis. ...Keep reading ...

Permutation in String

By aniket verma

● Published Nov, 2021

This article will brief you on how we can solve the problem of Permutation in String....Keep reading ...

Minimum Number of Distinct Elements after Removing M items

By Abhishek Nayak

● Published Oct, 2022

In this blog, we will discuss the hashmap approach using which we can print the minimum number of distinct elements after removing m items....Keep reading ...

Check If Two Given Sets Are Disjoint

● Published Jul, 2022

We will discuss one of the basic questions related to the DSU, which is How to check if two given sets are disjoint....Keep reading ...

Check if Two Arrays are Equal or Not

By Sneha Mallik

● Published Jul, 2022

This blog will cover the problem statement to check if two arrays are equal or not. We will be discussing the algorithm, implementation and time and space complexity....Keep reading ...

Count maximum points on same line

● Published Jul, 2022

In this article, we will see the solution to an array problem Count maximum points on same line....Keep reading ...

Count pairs with given sum

● Published Jul, 2022

This article incorporates how to count pairs with a given sum....Keep reading ...

Count quadruples from four sorted arrays whose sum is equal to a given value x

By Gaurav Bashisht

● Published Jul, 2022

This article is about the “Count Quadruples from four stored arrays whose sum is equal to a given value x” problem, which can be solved using hashing technique. In this blog we will learn about how to solve this problem with their examples and algor...Keep reading ...

Count pairs whose products exist in array

● Published Jul, 2022

This article incorporates how to count pairs whose products exist in an array....Keep reading ...

Count Items Common to Both the Lists But With Different Prices

● Published Jul, 2022

Meta Description: This article incorporates a detailed discussion on the problem Count items common to both the lists but with different prices along with implementation in different languages. ...Keep reading ...

Find All Duplicates in an Array

● Published Nov, 2021

This article will brief you on the problem of finding all duplicates in an array ...Keep reading ...

Find Number of Employees Under Every Manager

By Gaurav Bashisht

● Published Jul, 2022

This blog is about “ find number of employees under every manager” problem, which can be solved using hashing techniques. In this article we will learn about how to solve this question with their examples and algorithms. We will also see the impleme...Keep reading ...

Find duplicates in a given array when elements are not limited to a range

By Anuradha_8356

● Published Jul, 2022

This blog discusses unordered_map for hashing methods to find duplicates in a given array when elements are not limited to a range. ...Keep reading ...

Find Missing Elements of a Range

● Published Jul, 2022

In this blog, we will discuss the different methods to solve the problem of finding missing elements of a range, using both the native approach of sorting an array and the optimal approach of Hashing. ...Keep reading ...

Find The Top Three Repeated Elements In An Array

● Published Jul, 2022

In this blog, we will discuss the top three elements in an array problem including the algorithm and the implementation using hashmap in different languages. ...Keep reading ...

Find top k numbers in a stream

● Published Jul, 2022

This article incorporates how to find top k numbers in a stream....Keep reading ...

Find elements which are present in one array but not in other

By Anuradha_8356

● Published Jul, 2022

In this blog, we will discuss the different approaches to find the elements which are present in one array but not in another array. ...Keep reading ...

Longest Consecutive Sequence

By Kushleen Waraich

● Published Nov, 2021

In this blog, we will be mastering a very famous interview problem i.e., Longest Consecutive Subsequence along with its approaches and implementation in C++, Java, and Python language. ...Keep reading ...

N Repeated Elements in Size 2N

By Firdausia Fatima

● Published Dec, 2021

In this blog, we’ll solve the problem ‘N Repeated Elements in Size 2N’ by using a map, set, and compare....Keep reading ...

Group words with same set of characters

By devika varshney

● Published Jul, 2022

We will go through the problem statement to group words with same set of characters using hashing method, including the algorithm, code, and its complexities in this blog....Keep reading ...

Print All Distinct Elements Of A Given Integer Array

By Aditya kumar

● Published Jul, 2022

In this article, we will solve a very famous problem, i.e., Print All Distinct Elements Of A Given Integer Array....Keep reading ...

Remove the Minimum Number of Elements Such that No Common Element Exist in both Array

● Published Jul, 2022

In this article, we will look into an important coding question, Remove the Minimum Number of Elements Such that No Common Element Exist in both Array....Keep reading ...

Change the Array into a Permutation of Numbers from 1 to n

● Published Jul, 2022

In this article, we will look into an important coding question, Change the Array into a Permutation of Numbers from 1 to n....Keep reading ...

Custom Sort String

By Saksham Gupta

● Published Dec, 2021

In this blog, we will discuss one of the famous and important questions from the interview perspective, i.e., Custom Sort String. ...Keep reading ...

Fair Candy Swap

By Soumya Agrawal

● Published Nov, 2021

In this blog, we will discuss the problem of swapping candies and see the various implementations of this problem....Keep reading ...

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