HashSet Archives - GeeksforGeeks

Optimizing Range Selection for Maximum Sum of B[]

Last Updated: 30 November 2023

Given two arrays A[] and B[] of length N. Then your task is to choose a range [L, R] in such a way that both the conditions are met, Then the task is to output the Maximum...read more

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Minimize Range of the Array

Last Updated: 31 January 2024

Given an array A of size N. In one operation, you can select any number from the array and reduce it to a divisor greater than 1. For example, you can reduce 16 to 2, 4, 8...read more

Find the Intersection of Two HashSets in Java

Last Updated: 28 April 2025

HashSets is a type of Collection in Java that cannot contain any duplicate values. It is often used when we need to maintain a unique data set in our application, it uses ...read more

Convert a HashSet to a LinkedList in Java

Last Updated: 25 January 2024

In Java, HashSet and LinkedList are linear data structures. These are majorly used in many cases. There may be some cases where we need to convert HashSet to LinkedList. S...read more

How to Implement a Bidirectional Map Using Two HashSets in Java?

Last Updated: 07 February 2024

Bidirectional maps are also known as two-way maps or dual maps. These provide a convenient way to establish a relationship between keys and values in both directions. In J...read more

How to Iterate Over a HashSet Without an Iterator in Java?

Last Updated: 01 February 2024

In Java, we can iterate over a HashSet without using an Iterator. For this, we need two methods. We can directly loop through the elements of the HashSet.In this article, ...read more

Deep Copy of a HashSet in Java

Last Updated: 02 February 2024

HashSet is used to store a unique set of values in Java. It is a class that stores values and provides efficient access. As we know Java uses call-by-reference. So, if we ...read more

How to Create a HashSet With a Predefined Capacity in Java?

Last Updated: 01 February 2024

In Java, we can create HashSet with a predefined capacity by creating a constructor and passing the capacity as a parameter to it. We have to initialize the capacity using...read more

How to Convert List of Lists to HashSet in Java Using Lambda Expression?

Last Updated: 12 February 2024

A lambda expression is a short code block that accepts parameters and outputs a result. Similar to methods, lambda expressions can be used directly within the body of a me...read more

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How to Serialize and Deserialize a HashSet in Java?

Last Updated: 28 April 2025

Serialization is the technique of converting an object's state into a byte stream. The main purpose of serialization is to save the state of an object so that it can be re...read more

How to Create Subsets of a HashSet based on Specific Criteria in Java?

Last Updated: 20 February 2024

In Java, HashSet provides a dynamic collection of unique elements. Sometimes, we may need to create subsets of a HashSet based on specific criteria. In this article, we wi...read more

How to Create a HashSet with a Custom Initial Load Factor in Java?

Last Updated: 14 February 2024

Java HashSet is a simple data structure provided by the Java Collection Framework that provides efficient storage and enables the storage of unique objects. One of the par...read more

How to Convert a HashSet to JSON in Java?

Last Updated: 28 April 2025

In Java, a HashSet is an implementation of the Set interface that uses a hash table to store elements. It allows fast lookups and does not allow duplicate elements. Elemen...read more

How to Convert List of Lists to HashSet in Java?

Last Updated: 26 February 2024

In Java, Collections like lists, and sets play a crucial role in converting and manipulating the data efficiently. The Conversion of a List of Lists into a HashSet is main...read more

What is the difference between Set vs Hashset in C++?

Last Updated: 23 May 2024

In C++, both set and HashSet(also called unordered_set) are used to store elements but they have different properties and use cases. In this article, we will learn the key...read more