# Category: Arrays

## Java program to find the largest element in array

Objective– Given an array of numbers, write a java program to find the largest element in the given array. Example: int [] a = {1, 5, 3, 9, 2, 8, 2} Largest Element: 9...

## Find three smallest elements in a given array

Objective: Given an array of integers, write an algorithm to find the three smallest elements in the array. Example: Int [] a = { 6, 8, 1, 9, 2, 10}; Output: 1, 2, 6...

## Stack Java Class – Explained

Earlier we saw about Stack and its implementation using Linked List. Java has a built in class for Stack. In this article we will discuss about it in detail. First brief about Stack. What...

## Check if array contains all unique or distinct numbers.

Objective: Given an array of integers, write a program to check if array contains all unique numbers. Example: Integer [] arrA = { 1, 2, 3, 6, 4, 9, 8}; Output: Array has all...

## Product of all Unique elements in a given array.

Objective: Given an array of integers which contains duplicates as well. Write a program to find the product of all unique elements in the array. This problem is also referred as find the product...

## Find first three largest elements in a given array

Objective: Given an array of integers, write an algorithm to find the first three largest elements in the array. Example: Int [] a = { 6, 8, 1, 9, 2, 1, 10}; Output: 10,...

## Find two smallest elements in a given array

Objective: Given an array of integers, write an algorithm to find the two smallest elements in the array. Example: Int [] a = { 6, 8, 1, 9, 2, 10}; Output: 1, 2 Int...

## Front and Back Search in an Array

Objective: Given an unsorted array of numbers and a number ‘x’, write a java program to search the number ‘x’ in the array and return its index else return -1. Example: Int [] a...

## Print all Unique elements in a given array

Objective: Given an array of integers which contains duplicates as well. Write a program to print all unique elements in the array. This problem is also referred as print all distinct elements in the...

## Find Number of reverse pairs in an array

Objective: Given an array of integers A[],find no of reverse pairs means no of (i, j) pairs where i < j and A[i]>A[j]. Example: A[] = {10, 3, 4, 2, 5, 7, 9, 11}...

## Find first two largest elements in a given array

Objective: Given an array of integers, write an algorithm to find the first two largest elements in the array. Example: Int [] a = { 6, 8, 1, 9, 2, 1, 10}; Output: 10,...

## Java Program to find Sum the elements of an Array

Objective: Given an array of integers, write a java program to find the sum of all elements Example: Input [] = {20, 30, 40, 10, 5, 2, 60, 73} Output: 240 Approach: Do a...

## Rotate the given array in cycles

Objective: Given an array of integers, write a program to rotate the array in cyclic manner by one. Example: Int a [] = {1, 2, 3, 4, 5} Output:  {2, 3, 4, 5, 1}...

## Heap Sort – Java Implementation

What is Heap Sort?? Heap sort is comparison based sorting algorithm. Heap sort is considered as improved selection sort, it divides the input into sorted and unsorted region. The improvement from selection sort is...

## Find no of reverse pairs in an array which is sorted in two parts in O(N)

Objective: Given an array of integers A[] which is sorted in two parts (both parts are individually sorted), find no of reverse pairs means no of (i, j) pairs where i belongs to the...