Sum Root to Leaf Numbers is a popular interview problem which is asked in companies like Google & Microsoft. You can find this question in LeetCode & InterviewBit. We have been given a binary tree where each node can contain any number between 0-9. 2 / 4 8 For the above tree, there are two … Read more
This is common interview question. There can be a variant where we would have to find Least Common Ancestor (LCA) of a Binary Search Tree (BST). But here we will concentrate our solution for a normal unordered Binary Tree. This question is asked in companies like FaceBook, Google, Adobe, Microsoft & Amazon. You can find … Read more
Many of us use Collabedit frequently to conduct technical interviews. It is a easy to use online code editor where code can be shared between interviewer & interviewee. It supports most of the common programming languages available like Java, C++, Python, PHP or JavaScript. But recently I have seen Collabedit having server problems frequently. Sometimes the website … Read more
Sliding Window Maximum problem is a question that is asked in different companies like Google, Amazon & Walmart. You will find the question in websites like LeetCode and InterviewBit. An array of integers A is given to us. We have a sliding window of size B which is moving from the left of the … Read more
Problem: An array of integers A is given of size N. A represents a histogram i.e A[i] denotes height of the ith histogram’s bar. Width of each bar is 1. This is a question you will find in LeetCode or InterviewBit and asked in interviews of Google, Amazon or Facebook. Above you can see a histogram with … Read more
There are several ways to add code box in Blogger blog posts. Many of them would suggest to edit blogspot template and add third-party CSS links. But I prefer a way that doesn’t require any tampering or modification of blogspot template. First of all, it is risky & you may corrupt template HTML. Secondly, if … Read more
This is a common question asked in interviews of Microsoft, Google & Facebook. You might have stumbled upon this question in LeetCode or InterviewBit. Given a collection of numbers that might contain duplicates, return all possible unique permutations. Input: nums = [1,1,2] Output: [[1,1,2], [1,2,1], [2,1,1]] Here is the working solution for this problem in … Read more
We are fond of one db session per request pattern. For web applications with JPA & Hibernate, it is good strategy in common cases. But for some long-running requests (definition of long-running depends on your use case, maybe 500 ms or 2 s), we need to tweak when we are actually acquiring a db connection … Read more
Here is a fully working Java solution for evaluation of Reverse Polish Notation (Postfix Expression). This is a common interview question that is asked in Google, Yahoo and Facebook. Solution Java class doesn’t have a main() method. You can write a main() method and call evalRPN() method from there. Input argument to evalRPN() method should … Read more
Here is the fully working Java code solution for sorting a Linked List. You can find the same problem as an exercise in LeetCode. I have used Merge Sort here. The expectation here is that the code should run in O(n log n) time complexity and space complexity should be O(1). The below java program … Read more