XpressBees Software Developer Interview Questions and Answers for Experienced

The question asks to input an array and print the repeating characters.

• Iterate through the array and store each element in a hash table or dictionary.

• If an element already exists in the hash table, it is a repeating character.

• Print all the repeating characters found.

Program to find the second minimum in an array.

• Sort the array and return the second element.

• Initialize two variables to store minimum and second minimum values.

• Loop through the array and update the variables accordingly.

To find the longest palindrome in a given string.

• Iterate through the string and check for palindromes of odd and even lengths.

• Keep track of the longest palindrome found so far.

• Use two pointers to check if the substring is a palindrome.

• If the substring is a palindrome and its length is greater than the current longest palindrome, update the longest palindrome.

Find the next higher number with equal number of ones in binary representation.

• Convert input number to binary

• Count number of ones in binary representation

• Increment input number until binary representation has equal number of ones

• Convert incremented number to decimal

Find the duplicate number in an array of 10 numbers with only 2 steps.

• Use a hash set to keep track of visited numbers.

• Iterate through the array and check if the number is already in the set.

• If it is, then it is the duplicate number.

• If not, add it to the set.

• At the end, the duplicate number will be found.

Program to print elements of a linked list in reverse order using same single linked list

• Traverse the linked list and push each element onto a stack

• Pop elements from the stack and print them in reverse order

To check the occurrence and correctness of HTML tags, we can use various tools and techniques.

• One way is to use a browser's developer tools to inspect the HTML code and see the tags and their frequency.

• Another way is to use an online HTML validator tool that checks for correct syntax and tag usage.

• We can also use programming languages like Python to parse HTML and count the occurrence of each tag.

• Regular expressions ca...read more

Reverse a linked list using iterative and recursive methods.

• Iterative method involves traversing the list and changing the pointers to reverse the order.

• Recursive method involves calling the function recursively on the next node and changing the pointers.

• Both methods have O(n) time complexity and O(1) space complexity.

• Example: 1->2->3->4->5 becomes 5->4->3->2->1.

Clone a linked list with a random pointer.

• Create a new node for each node in the original list.

• Use a hash table to map the original nodes to their clones.

• Iterate through the original list again and update the random pointers of the clone nodes.

Diameter of a binary tree is the longest path between any two leaf nodes.

• Calculate the height of left and right subtrees recursively.

• Calculate the diameter recursively using the formula max(left_height + right_height + 1, max(left_diameter, right_diameter)).

• Return the maximum diameter.

To find interchanged terms from an AP series

• Identify the common difference between terms

• Swap the positions of adjacent terms

• Check if the new series is also an AP

• Repeat until no more interchanged terms can be found

Database indexing is a technique to improve the performance of database queries.

• Indexing creates a data structure that allows for faster retrieval of data.

• Indexes are created on one or more columns of a table.

• Queries that use indexed columns can be executed faster.

• Indexes can be clustered or non-clustered.

• Clustered indexes determine the physical order of data in a table.

• Non-clustered indexes create a separate structure...read more

Design a stack that supports getmin in O(1) time and O(1) space complexities.

• Use two stacks, one for storing the actual values and the other for storing the minimum values.

• When pushing a new value, check if it is smaller than the current minimum value and push it to the minimum stack if it is.

• When popping a value, check if it is the current minimum value and pop it from the minimum stack if it is.

• To get the minimum val...read more

Binary tree traversal is the process of visiting each node in a binary tree exactly once in a specific order.

• There are three main types of binary tree traversal: inorder, preorder, and postorder.

• Inorder traversal visits the left subtree, then the root, then the right subtree.

• Preorder traversal visits the root, then the left subtree, then the right subtree.

• Postorder traversal visits the left subtree, then the right subt...read more

LRU cache is a data structure that stores the most recently used items and discards the least recently used items.

• LRU stands for Least Recently Used

• It has a fixed size and when the cache is full, the least recently used item is removed to make space for a new item

• It uses a combination of a doubly linked list and a hash map to achieve O(1) time complexity for both insertion and deletion

• Example: A web browser cache that ...read more