Nowfloats Technologies Lead Engineer Interview Questions and Answers for Experienced

Find sum of k smallest numbers in a BST.

• Traverse the BST in-order and add the k smallest numbers to a sum variable.

• Use a priority queue to keep track of the k smallest numbers.

• If k is greater than the number of nodes in the BST, return the sum of all nodes.

• If k is 0, return 0.

Design algorithm and database for seat booking system of BookMyShow and handle failed payments.

• Create a database with tables for movies, theaters, seats, bookings, and payments

• Use a locking mechanism to prevent double booking of seats

• If payment fails, release the locked seats and notify the user

• Write a query to get the timestamp in SQL: SELECT CURRENT_TIMESTAMP;

Code for time stamp in C

• Use the time.h header file

• Call the time() function to get the current time in seconds

• Convert the time to a string using strftime() function

• Use the format string to specify the desired format of the time stamp

Rearrange array in consecutive pair multiplication in descending order.

• Create a new array to store the multiplied values

• Use a loop to iterate through the original array and multiply consecutive pairs

• Write a compare function to sort the new array in descending order

Code to rearrange an array in maximum-minimum form.

• Sort the array in descending order.

• Create a new array and alternate between adding the maximum and minimum values from the sorted array.

• Return the new array.

• Time complexity: O(nlogn)

• Space complexity: O(n)

stoi() function converts a string to an integer.

• stoi() is a C++ function that takes a string as input and returns an integer.

• It is used to convert a string of digits into an integer.

• It can also handle negative numbers and ignore leading whitespace.

• Example: int num = stoi("123"); // num is now 123

Code for finding the longest common substring in an array of strings.

• Iterate through the first string and check for all possible substrings

• Check if the substring is present in all other strings

• Keep track of the longest common substring found so far

• Return the longest common substring

Answers to common technical questions in a software engineering interview

• A transaction in DBMS is a sequence of operations that must be treated as a single unit of work. ACID properties ensure reliability and consistency of transactions.

• A thread is a lightweight process that shares memory and resources with other threads in the same process. A process is a separate instance of a program.

• Common Linux commands include ls...read more