“””Write a memory allocation function (and corresponding free function)that returns a block of memory aligned to the specified alignment value.You may assume that the alignment is a power of 2 (1, 2, 4, 8, 16, …).“”” This Google systems-level question asks you to implement your own malloc-like function that guarantees the returned pointer is aligned…

“””We have an embedded environment with a very simple operating system. Part of the facilities provided to us is a single hardware timer.The goal is to implement multiple timers, each with their own callback, based on this single timer.The hardware timer can be set with the following function:void set_hw_timer(int relative_timeout_ms);After relative_timeout_ms milliseconds have elapsed, the…

“””// Write a node class to be used in a tree. A Node should contain exactly one integer and have zero or more children.“”” “””Define: a “descending tree” is a tree such that for each node n, the value of n is larger than the value of any descendant of n. Write a function that…

“””You and a friend have received a special gold chain as a gift.The chain links each have an integer weight, not necessarily the same.You and your friend must choose one of the links to be removed and provided to charity, after which the chain will be reconnected.After that, you can choose one place along the…

“””Imagine a log file that abridges chats. An example chat might be: 10:00 <john> hi!10:01 <maria> hello!10:07 <john> can you link the design? where john said 6 total words and maria said 1. Your goal is to present the top N most talkative users in descending order. You need to write a function that takes…

An arithmetic sequence is a list of numbers with a definite pattern. If you take any number in the sequence then subtract it from the previous one, the difference is always a constant. A good arithmetic sequence is an arithmetic sequence with a common difference of either 1 or -1. For example, [4, 5, 6]…

This problem is a standard weighted random selection. Build a prefix-sum array based on city populations and map a random value into one of the prefix intervals. This guarantees output probabilities match the weight distribution, and repeated queries remain efficient. The key is prefix sums plus binary search for fast selection. The BST property allows…

The solution uses a stack to simulate function calls. A“begin”event pushes a new frame and pauses the previous function, while an“end”event pops the function and accumulates its exclusive time based on timestamp differences. Properly tracking the previous timestamp is essential to handle nesting correctly. The VOprep team has long accompanied candidates through various major company OAs and…

Standing on the left side gives the leftmost node of each level, but the ordering must be reversed from bottom to top. Standing on the right side gives the rightmost node level by level from top to bottom. The problem is solved with BFS level traversal and extracting the appropriate visible node at each level….

This is the 2D extension of the range counting problem. Build a 2D prefix-sum matrix pre[i][j] for ones in the rectangle from (0,0) to (i,j), then answer any subgrid query in O(1) time using the inclusion–exclusion formula. It tests understanding of 2D prefix sums and careful boundary handling The VOprep team has long accompanied candidates through various…