DS Interview Question Archives -

Program to Move zeros to end of integer array in java (example)

Given an array containing integers (+ve, -ve & 0), we would like to move zeros to end of array. We […]

Find second smallest element in an array of integers (java / example)

Given an array of integers in java. Print second smallest element in an array (in single iteration). We have already discussed

Implement two stacks using single array in java (example)

Given an array of integers in java. Create two stacks using single array. We shall able to perform push &

Find second largest element in an array of integers (java / example)

Given an array of integers in java. Print second largest element in an array (in single iteration). Example – find second largest

Create/ implement stack using single linked list in java (generics /example)

Create stack in java using linked list. We will implement stack using java generics. We will create a stack class,

Create or implement stack using array in java (with example)

Create or implement stack in java using array as underlying data structure. We will create stack class having following methods

Find missing number or element from duplicated array in java

Given two arrays, one array is almost duplicate array of another array. Arrays are duplicated except one element. e.g. array1[] =

Find maximum sum subarray in java using Kadane’s algorithm

Given an array containing positive & negative integers. We would like to find subarray having maximum sum. We will use

Reverse an integer array in java using iterative & recursive algorithm

Given an integer array in java. Reverse input array using iterative & recursive algorithm. Example to reverse an integer array

Prime number generator in java using Sieve of Eratosthenes algorithm

A prime number is a natural number greater than 1 that has no positive divisors other than 1 & itself. e.g.Number 7

Find union of two sorted integer or number arrays in java (example)

Given two sorted integer arrays containing unique or distinct elements. We would like to find out the union of two

Find intersection/common elements of two sorted integer arrays in java (example)

Given two sorted arrays containing distinct elements. We would like to find out the intersection of two sorted arrays. Intersection

Replace every element in integer array by greatest number on its right (java/ example)

Given an array of integers in java. Replace every element of array with greatest number on its right. The right

Find leader elements/numbers in integer array (java/example/iterative algorithm)

Given an integer array in java, find out the leader elements in an array. What is leader element in an

Majority element in integer array (Boyer Moore’s voting algorithm) in java

Given an integer array in java, find the majority (element exist more than half element) element in an array using Boyer Moore’s voting algorithm.

Find a missing number in an array of distinct integers in java (example)

Given an array containing n-1 distinct positive numbers range from 1 to n. e.g suppose n = 5, array will contain 4 unique

Find a number occurring odd number of times in integer array using java

Given an array of integer containing positive numbers. All number in an array is occurring even number of times except one

Dutch national flag problem or Sort array containing 0s, 1s & 2s in java

Given an array containing unsorted integers 0,1 & 2. Sort the given input array using non recursive method. Dutch national flag

Sort an integer array using mergesort algorithm in java (with example)

What is merge sort algorithm? Merge sort(or MergeSort) is efficient, comparison based algorithm. The properties of merge sort algorithm are

Sort integer array in java using quicksort algorithm (example)

Given unsorted array in java, Sort integer array – Quick sort (partition-exchange) algorithm. Quick sort is divide & conquer algo. complexity : O(n log n).

Sort an integer array using insertion sort algorithm in java (with example)

What is insertion sort algorithm? Insertion sort is a sorting technique. The elements are inserted at an appropriate place in an

Sort an integer array using selection sort algorithm in java (with example)

What is selection sort algorithm? Selection sort is sorting technique used to sort the elements in list data structure like array.

Sort integer array using bubble sort algorithm in java (example)

Given an unsorted array in java. Sort the given input array using bubble sort algorithm. Bubble sort is a sorting

Classify or segregate array containing even & odd numbers in java (example)

Given an array containing even and odd number in java. We would like to classify the even and odd numbers.

Sort an integer array containing 0 & 1 in java (example)

Given an integer array containing 0 and 1. We would like to sort input array. Zeros will be left end

Check if array contains duplicate elements using java (example)

Problem Statement: Given an array of integer, we would like to find out, whether array contains any duplicate elements. The

Find maximum & minimum element in array (java / example)

Given an array of integers , find out maximum & minimum number in array using linear search. e.g. input array is { 50,

Find/search element in sorted integer array (java/binary search algorithm/iterative)

Given sorted integer array in java. Find or search element/integer in an array using binary search algorithm (with example). Binary

Find element in an array using binary search algorithm in java (recursive)

Binary search is a divide and conquer algorithm. Divide and conquer algorithm is process of dividing the input data-set after

Remove duplicate nodes from sorted singly linked list in java(example/ algorithm)

Given the sorted linked list, we need to remove duplicates from the linked list. There should not be any duplicate nodes in the linked linked list. Suppose we are given the linked list as shown in Fig 1, there are some duplicate elements in the sorted linked list.