Java

9.4K+ posts

Last Updated: 31 January 2026

In Java, strings are immutable, meaning their values cannot be changed once they are created. To support efficient string manipulation, Java provides mutable classes like ...read more

Java

Sort students by marks in Java

Last Updated: 30 January 2026

The arrays roll[] and marks[] store student roll numbers and their corresponding marks. The objective is to reorder the roll numbers such that they follow the descending o...read more

Java

Meeting Maximum Guests in Java

Last Updated: 29 January 2026

Given two arrays, arr[] and dep[] representing the arrival and departure times of guests at a party, where each arrival corresponds to a departure at the same index, the g...read more

Java

Sort an Array According to Another Array in Java

Last Updated: 29 January 2026

Given two arrays of equal size, an integer array a[] and a character array b[], each character is associated with an integer at the same index.Sort the character array b[]...read more

Java

The thief problem in Java

Last Updated: 29 January 2026

Given an array arr[] and an integer K, find the maximum possible sum of any K elements.Examples:Input: arr[] = {3, 7, 2, 5, 12, 30}, K = 3 Output: 49Explanation: Pick 30, ...read more

Java

Keeping indexes after sorting in Java

Last Updated: 28 January 2026

Given an integer array, sort its elements in ascending order while retaining and displaying their original indexes, ensuring the initial positions of elements are preserve...read more

Java

Comparator Methods and Examples

Last Updated: 29 January 2026

The Comparator interface in Java is used to define custom sorting logic for objects. It allows sorting collections based on different attributes without modifying the orig...read more

Java

Design a DS for prices - duplicates allowed

Last Updated: 28 January 2026

Design a data structure that stores items with associated prices (duplicates allowed) while supporting fast insertion, lookup by price, and sorted as well as range-based r...read more

Java

Design a DS for item prices in Java

Last Updated: 29 January 2026

Given a collection of items with their corresponding prices, design a data structure that efficiently supports the following operations:add(price, item): Adds a new item a...read more

Java

Ceiling on right in Java

Last Updated: 28 January 2026

Given an integer array, the goal is to find the ceiling on the right for each element - the smallest number greater than or equal to it that appears after it. If no such n...read more

Java

Design DS for balance in Java

Last Updated: 28 January 2026

Design a data structure to store user IDs and their corresponding balances in an e-Wallet system. The data structure must support insertion, update, and retrieval of balan...read more

Java

Print Frequencies in an Order in Java

Last Updated: 28 January 2026

Given an array of integers, determine the number of occurrences of each distinct element and output them in the same sequence in which they first appear in the array.Examp...read more

Java

Purchasing maximum items in Java

Last Updated: 28 January 2026

Given an array of item costs and a total sum, determine the maximum number of items that can be purchased without exceeding the given sum.Example:Input: costs[] = {8, 3, 6...read more

Java

Generate numbers with given digits in Java

Last Updated: 29 January 2026

Generating numbers using a given set of digits is a common problem in Java programming.It helps in understanding recursion, permutations, loops, and number construction lo...read more

Java

Design a data structure with min/max operations in Java

Last Updated: 29 January 2026

Design a data structure that supports the following operations efficiently to achieve O(1) time complexity for retrieving minimum and maximum elementsinsert(x): Insert an ...read more

Java

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