Computer Scientist 1

Given a (n * n)  2-D grid of 0s, 1s and 2s. We need to sort the array from top-left to bottom-right so that all the 0s are aligned top and then right, followed by 1s and finally 2s towards bottom-right. Improve the complexity, if possible.

Given a 2D grid having N Rows and M Columns. Each cell of the grid has a character among [ 'U', 'L', 'D', 'R' ] written on it, denoting Up, Left, Down, and Right respectively and indicating the direction in which it is permitted to move from that cell to its neighbor. Your task is to find the minimum number of cells whose direction value is required to be changed so that there exists a path from Top-Left to the Bottom-Right cell by following the directions written on the cells.

For example,

Consider the 2 * 2 grid

Let's call the four cells in the grid as A,B,C,D. In this grid, it is allowed to move from Cell A to Cell B, Cell B to Cell D, Cell C to Cell D and Cell D to Cell C. There are two paths that start from A and ends at D:

1) A->C->D
To follow this path we need to change the value of cell A to “D” and do not need to change the value of cell C. Therefore, the total change for this path is 1.

2) A->B->D
To follow this path we need not to change any of the cell values. Therefore the total changes for this path is 0.

As we can see the minimum changes required to reach the bottom-right cell is Zero therefore the answer is 0 in this case.

• They asked me about multi-threading, multi-processing, race condition and asynchronous computing.
• Then, the interview switched to Java basics—they asked me about memory storage, stack and heap, garbage collection, call-by-value and call-by-reference in Java.

You will be given a stream of numbers, and you need to find the 'kth' largest number in the stream at any given time.

As the stream of numbers can not be given during compile time, so you need to design a data structure which can accept infinite numbers and can return the 'kth' largest number at any given time.

The stream of numbers is nothing but a large collection of numbers from which integers are read at runtime, such as the user will never know the upper limit on the number of integers that will be read.

The implemented data structure must support the following operations:

1. add(DATA) :
   This function should take one argument of type and store it in its pool and returns the 'kth' largest number from the current pool of integers.

You will be given 'q' queries:

val - For this query, insert the integer into your current pool of integers and return the 'kth' largest integer from the existing pool of integers.

Note

 1. The maximum number of integers that will be given will always be under memory limits.

 2. You will also be given an initial pool of integers whose size equals k.

 3. The maximum number of queries will be less than 10^5.

 4. The 'kth' largest element is not the 'kth' distinct element but the 'kth' largest element in the sorted order.

 5. There will be at least one query of type 2.

Design a low-level system for a search engine to search through a plethora of PDFs. Essentially, it was a search service to look for keywords within a collection of PDFs. The interviewer was interested in understanding the class structures, design patterns used, and some concepts related to indexing and databases. In the end, he switched to asking questions about my machine learning college project and how I could apply recommendations in search bars using ML.