CareerCup

Design an e-commerce site for infants shopping.

Design google for old people.

You have a file with 100 billion URLS, find first unique URL.

Design a data structure for following operations in O(1) time.:
insert
remove (FIFO)
find MODE

Design an LRU cache, where you remove an element not only by time lapsed since last used but also by a cost associated with each element. F(t, c) is a method to find weight for each element. Where c is cost and t is time since last used.

How would you debug a Linux program taking too much memory.

There are 2 sets A and B of numbers where numbers are keep coming at high speed. At any given time, you need to find 'A UNION B', 'A INTERSECTION B', 'A - B' and 'B - A'.

How will you store numbers and how will you find these value in real time?

There are few sets with some numbers. And you are given an array of numbers. Find combination of sets with minimum number of sets, union of which have all these numbers.

Example:
input sets:
A => [1,2,3]
B => [2,5,8]
C => [1,4,5]
D => [3,5,8]

Array to find:
{3,4,8}

Answer:
C + D

How would you implement PIPE functionality in UNIX systems. Like "tail -f xyz.log | grep amazon"

How would you implement trending topics for twitter. Think at large scale as well.

Please elaborate your assumptions as well.

Design a system where you can reutrn top 20 queries made in last 24 hours to users.

Think on the scale of Google and Yahoo. How would you store data. What will be your data structures, algorithm to get that data.Describe your assumptions etc.

For simplicity, you can assume that every web server create a log file with query and timestamp.

You have an API for compressing 64 Bytes block of data. How would you implement products like zip/winzip/gzip etc from that.

You can assume that to compress a larger file you can just add compressed block of smaller parts.

Please write your assumptions clearly. Be it system etc.