CareerCup

Give a large multi MB byte file in memory, a system handles delete requests for segments typically of the order of bytes. The system has a constraint that individual purge requests of byte segments are expensive, so that the no. of purges are a minimum.

Eg. a 5 MB file receives delete requests for offsets (1, 100), (250, 550),(1000, 1200), (400, 600), (800, 900), (1100, 1150)

Effective delete requests - (1, 100) , (250, 600), (800, 900), (1000, 1200)

The users of the system always go by the absolute byte ordering of the file. Eg. if byte 1 is deleted, the users of the system will reference the actual byte 2 as byte 2.

What data structure would you use to store these intervals such that the following operations are efficient 1. Looking up an interval 2. Inserting a new interval that has no overlap with existing ones 3. Inserting a new interval that has partial overlaps with existing intervals. This would involve collapsing the existing intervals with the new interval to form a single large interval. Eg. Interval cache: {(1, 100), (250, 550), (1000, 1200)} , new interval : (400, 700) -> Interval cache: {(1,100), (250, 700), (1000, 1200)}

Given an mXn Sorted matrix and a value X. Every row is sorted and first number of every row is greater than last number of previous row Find the value X in most efficient way.

Given a Binary tree and value X. Find X in the tree and return its parent

X:

10
4 3
5 7 9 8

If X = 7, return 4

Given a list of list of positive integers, find all pairs of list which are having more than 3 elements overlapping.
What is the complexity.

Design OO food delivery app catering to use cases -
1) User can search different restaurant
2) User can select a restaurant
3) User sees a menu
4) Restaurant can change the menu any time
5) User adds an item from menu
6) User orders the food
7) User can track the order in real time
8) User can cancel the order
9) User pays for the order

Design food delivery app (OO design). Cater to use cases like search for different restaurants, selecting a restaurant, select an item from menu, menu can be updated in real time by restaurant, order the food, customer keeps track of the order in real time, payment for the order, cancel the order etc.

Design Uber low level OO design. Cater to use cases like search for a ride, different category of rides, select a ride, registration for a user and driver, paying for ride etc.

Given a dictionary and an char array print all the valid words that are possible using char from the array.

Ex- char[] arr = {'e','o','b', 'a','m','g', 'l'}

Dict - {"go","bat","me","eat","goal", "boy", "run"}

Print - go, me, goal.

We can pre-compute as much we want but the query time must be optimal.

Given input which is vector of log entries of some online system each entry is something like (user_name, login_time, logout_time), come up with an algorithm with outputs number of users logged in the system at each time slot in the input, output should contain only the time slot which are in the input. For the example given below output should contain timeslots
[(1.2, 1), (3.1, 2), (4.5, 1), (6.7, 0), (8.9, 1), (10.3,0)]

/*
[
("Jane", 1.2, 4.5),
("Jin", 3.1, 6.7),
("June", 8.9, 10.3)
]

=>

[(1.2, 1), (3.1, 2), (4.5, 1), (6.7, 0), (8.9, 1), (10.3, 0)]

*/

How would you design Amazon Lockers?

Amazon Lockers - Customers can use these lockers to have their products delivered. These lockers are physically available to customers at the same or several nearby zip codes.

The amazon site was working just fine until yesterday. But in the past 24 hours processing the customer orders is taking a really long time.

How would you debug and fix the issue?

When I asked if anything had changed in the past 24 hours, I was told several new products had been added after which the performance issues were noticed.

Given the root of a Binary Tree along with two integer values. Assume that both integers are present in the tree.
Find the LCA (Least Common Ancestor) of the two nodes with values of the given integers.
2 pass solution is easy. You must solve this in a single pass.

You are given 2 lists -
List 1: List<Demand> is a list of Demand objects.
List 2: List<Supply> is a list of Supply objects.

Return a result fulfillment List<Demand,List<Supply>>.

This means each demand could be satisfied by more than one supplies.

class Demand
{
Date startDate;
Date expirationDate;
int quantity;
}

class Supply
{
Date startDate;
Date expirationDate;
int quantity;
}

The Demand and Supply refers to that of groceries. You must map supplies to a demand only if the supply still has at least 3 days remaining to its expiration before the demand can be fulfilled.
A demand is said to be fulfilled 24 hours after all demands have been mapped to correspondingly available supplies.

Given a string with only parenthesis. Check if the string is balanced.
ex -
1) "<({()})[]> is balanced
2) "<({([)})[]> is not balanced

Write code for the partition subroutine in Quicksort.

How would you Design a HashTable?
In what ways would you attempt to address collisions?

Given that an external service gives a list of credit cards that have become fraud, design a fraud management system for a shopping website for bookings with fraud credit cards

Given a list of shops each of which have a list of toys with their prices and max number of children who can play with it at a time. Output the a list of best possible toy option from each shop given the number of children who are shopping.

ToyShopping
{

getListOfBestToysFromEachShop(List<Shop> shops);

}

Shop
{
int id,
List<Toy> listOfToys;
}

Toy
{
int toyId;
int shopId;
int price;
int maxChildren; //max number of children who can play with this toy
}

Design the classes for a Battleship Game. Write the attack function.

Write a program to check whether it is a valid binary tree or not. Check all test cases (e.g. No left Node case).

Given (a,b) can you reach to (c,d) if a and b can move either (a+b,b) or (a,a+b). Example a =1, b=4,c=5,d=9 then (1,4) -> (5,4) -> (5,9)

Design a logging system. The system contains multiple application servers which are logging the information to file system. In this scenario, we want to check and alarm in case an exception is thrown in any of the servers. We want a system that checks for appearance of specific words, "Error", "Exception", "Disk Full" etc. in the logs of any of the servers. How would you design this system?
What if we want to scale the system in future?

We need a functionality to block an user who makes more than 10 requests in last 5 minutes. You need to implement the following function.
{{
boolean block_user(int user_id)
{
//TODO: return true in case u want to block user
}
}}

object oriented design for robot vacuum cleaner.
write use cases, draw class diagram and interfaces
between them.

Design a deck of cards that can be used for different card game applications.

Please code out what you would need for the deck class and a card class.

Implement a deal method.

Design a system for searching strings in files present on a fileserver under a directory. there won't be any sub-directories. There could be more than thousand/lakhs files. And the file size could be in GBs. The matching line should be written to a single file. user will execute grep "string"
The sub-questions are
1) Design where the application executes on single machine.
2) Design where the application can execute on multiple machine.
3) Where could be the potential bottleneck.
4) What component would be bottleneck if 50 cores and slow disk.
5) What component would be the bottleneck if we 4 cores and fast disks.

You have two very large numbers that cannot be stored in any available datatypes. How would you multiply them?
How would you multiply more than two numbers?

How will you implement a dictionary.

Design a monitoring system for hotel booking site. Proper oops design.

Given two strings, print all the inter-leavings of the Strings in which characters from two strings should be in same order as they were in original strings.

e.g.
for "abc", "de", print all of these:
adebc, abdec, adbce, deabc, dabce, etc, etc