CareerCup

//Online Coding Assignment

As a member of the cab finder app team, you are tasked with implementing a CabFinder class that has the following minimal public interface:

class CabFinder implements CabStatusListener {
/**
* Initiates CabFinder. Called only once per app startup.
* @app An application object providing services implemented by
*      the rest of the application.
* @maxCabs Nearest number of cabs that can be returned to the user
*/
public void initialize(CabApp app, int maxCabs) {
  //Insert code here...
}

/**
* Gets nearest cabs within 1km of the current user’s location. 
* These must be the *nearest possible* @maxCabs in the 1km area.
* @return An unordered list of the nearest cabs.
*/
public Cab[] getNearestCabs() {
   //Insert code here...
}

/**
* Asynchronous Callback per CabStatusListener (see below). Called when the position of a cab has changed. 
*/
void onCabPositionChanged(Cab cab) {
   //Insert code here…
}

/**
* Asynchronous Callback per CabStatusListener (see below). Called when a cab’s availability changes.
* @cab The cab whose availability has changed
* @isAvailable true if the cab is now available, false otherwise
*/
void onCabAvailabilityChanged (Cab cab, boolean isAvailable) {
   //Insert code here…
}
}

Supporting Classes:
Here are the classes and utilities that are available for your use (you are not required to write any implementation for these classes)
/**
* Coordinates on a 2D map with a one meter granularity.
*/

class Position {
public int x;
public int y;
}

interface Cab {
	/**
      * Unique identifier of a cab.
      */
     int getID();
 
	/**
	* Gets the current position of the cab
	*/
  	Position getCabPosition();

	/**
	* Returns whether or not the cab is available
	*/
  	boolean isAvailable();
}

/**
* Provides services implemented by the rest of the Cab Application.
*/
interface CabApp {
/**
* Gets the current location of the user
*/
Position getUserPosition();

/**
* Returns an iterator that gives access to the list of all cabs in the city
*/
Iterator<Cab> getCabs();

/**
* Registers a CabStatusListener object for change notifications of cab object data.
*/
void register(CabStatusListener listener);
}

/**
* The CabStatusListener interface
*/
interface CabStatusListener {
/**
* Called when the position of a cab has changed.
* @cab The cab object
*/
void onCabPositionChanged(Cab cab);

/**
* Called when a cab’s availability changes.
* @cab The cab object
* @isAvailable true if the cab is available, false otherwise
*
*/
void onCabAvailabilityChanged (Cab cab, boolean isAvailable);
}

Find if 2 lists of rectangle are exactly equal. How would you sort the lists?

Given 2 quad-trees find the intersection of black-pixels.

Define a quad-tree for a black and white image. Count the number the of black pixels.

Given a large network of computers, each keeping log files of visited urls, find the top ten of the most visited urls.
(i.e. have many large <string (url) -> int (visits)> maps, calculate implicitly <string (url) -> int (sum of visits among all distributed maps), and get the top ten in the combined map)

The result list must be exact, and the maps are too large to transmit over the network (especially sending all of them to a central server or using MapReduce directly, is not allowed)

Having an infinite stream of numbers write a function to take an element with equal probability for each.

Given a class of block reader, read in unlimited string flow.

You are given a grid, with points on the intersections (think a map of streets, people are standing on random corners). Write code to calculate the point on the grid that is the shortest distance from every point on the grid.

Given a set top box:
a, b, c, d, e,
f, g, h, i, j,
k, l, m, n, o
p, q, r, s, t
u, v, w, x, y
z

Write code to give the character sequence given a word, For example, if the word is "CON", the function will print this:
Right//now we're at B
Right//now we're at C
OK//to select C
Down
DOwn
Right
Right
OK//to select O
Left//now at N
OK//to select N

note: Be careful when you're at Z. if you go to the right, you will get stuck.
Afterwards, the interviewer adds a space to the right of 'Z' to test the code.

Design and implement a class, which returns a random string value from a set with an arbitrary probability distribution given by an array of probabilities. Using an existing random number generator with a uniform distribution(e.g., Random.nextFloat()), you return the string for the random float value based on the strings probability distribution.

design a method which consumes an integer and output the corresponding column number in Microsoft Excel ( ex. A, B, C......Z, AA, AB....ZZ....)