This problem is a classic range query task. The optimal solution precomputes a 1D prefix-sum array where prefix[i] stores the number of ones up to index , then each query runs in O(1) time using prefix[end] – prefix[start-1]. It tests preprocessing, time–space trade-offs, and clean API design. The VOprep team has long accompanied candidates through various major…

The task is to evaluate an expression with only + and *, respecting operator precedence. Typical solutions use a stack to accumulate intermediate products, or track the current multiplication block during a single pass. The VOprep team has long accompanied candidates through various major company OAs and VOs, including Meta, Amazon, Citadel, SIG, providing real-time voice assistance,…

A classic weighted random selection question: build a prefix-sum array, generate a random number within the weighted range, and use binary search to find the correct index. Commonly tested in Meta interviews for probability distribution and prefix-sum logic The VOprep team has long accompanied candidates through various major company OAs and VOs, including Meta, Amazon, Citadel, SIG,…

This Meta interview question asks for all root-to-leaf path sums in a binary tree. A depth-first search is used to propagate the running sum, recording values when a leaf is reached. It tests recursion, tree traversal, and handling of leaf conditions. The VOprep team has long accompanied candidates through various major company OAs and VOs, including Meta,…

This problem tests arbitrary-base conversion where the number is stored as a linked list. The core idea is to extract the base-10 value, then repeatedly apply modulo and division to build the new-base list. It evaluates understanding of linked-list big-integer representation and digit extraction logic. The VOprep team has long accompanied candidates through various major company OAs…

Problem 1 — CICD Pipeline Dependency Ordering CICD Pipeline:- Different environments.- If nothing is in prod theDatamine the order in which we should deploy our resources. Questions:1. What are the inputs? [A,B] where A and B are resources. A depends on B – list of lists where each inner list is a dependency pair and…

This Microsoft interview problem focuses on weighted random selection. Given cities and their populations, the function should return a city name with probability proportional to its population. A common solution uses a prefix-sum array and binary search to map a random number to the correct weighted interval. The VOprep team has long accompanied candidates through various major…

There are 2 single linked list, one is ascending sorted, the other is descending sorted, write code to merge them together, result in ascending sorted. For example:L1: 1->2->3L2: 6->5->4 Result:1->2->3->4->5->6 Requirements:Time complexity: O(M + N), M is the length of L1, and N is the length of L2Space complexity: O(1) Please write code to solve…

Problem 1 Imagine you’re working on a language which only support Stack, but you need a Queue functionality to fulfill the requirement. Problem 2 Given:const a = 1;const b = ‘1’;What is the result of each of the following statements: a == ba === b!a === !ba + ba + +b These are typical Microsoft…

Recently, Microsoft interview activity has noticeably increased again. One thing that has always been true about Microsoft is that interview content heavily depends on the team — different teams test very different skills. This time, all three of my rounds followed the pattern of resume deep-dive + coding questions, with no system design and no…