How would you reverse the image on an n by n matrix where each pixel is represented by a bit?

If you were at Google what new product would you like to have developed and why?

Given an array of integers which is circularly sorted, how do you find a given integer.

The question was the following. I'm rephrasing the question to make it clear for everyone to understand:

- You are going on a one-way flight trip that includes billions of layovers.
- You have 1 ticket for each part of your trip (i.e: if your trip is from city A to city C with a layover in city B, then you will have 1 flight ticket from city A to city B, and 1 flight ticket from city B to city C.
- Each layover is unique. You are not stopping twice in the same city.
- You forgot the original departure city.
- You forgot the final destination city.
- All the tickets you have are randomly sorted.

Question are:
- Design an algorithm to reconstruct your trip with minimum complexity.
- How would you improve your algorithm.

Example:
- randomly sorted:
New York->London
San Francisco-> Hong Kong
Paris->New York
London->San Francisco

- sorted:
Paris->New York
New York->London
London->San Francisco
San Francisco-> Hong Kong

Most phones now have full keyboards. Before there there three letters mapped to a number button. Describe how you would go about implementing spelling and word suggestions as people type.

Implement on a board a shortest path algorithm when traveling from point A to point B on a board. Once you produce a solution, they throw modifications to an initial problem like what if you know that points x, y, z cannot be used in a path.

Write a program to find depth of binary search tree without using recursion

Find the maximum rectangle (in terms of area) under a histogram in linear time.

Which wireless channel should you choose for you home wifi, considering there is no interference on any of them.

Do you have time to do a coding exercise?

Describe recursive mergesort and its runtime. Write an iterative version in C++/Java/Python