This programming challenge is expected to take you around 2 hours.

You are given a list of two-dimensional axis-aligned rectangular boxes that are either contained within or disjoint from (non-overlapping with) one another. They therefore partition the plane into a number of regions. The unbounded region, which lies outside all of the boxes, is classified as “sea”. All other regions are classified either as “sea” or as “land”, subject to the constraint that no two regions that share a boundary may share the same classification. The task is to output the number of regions classified as “land”.

You can expect each box to be defined in terms of the Cartesian coordinates of its minimum corner {a, b} and its maximum corner {c, d} such that a < c and b < d. If you make any other assumptions as part of your solution then please make comments in the code. If there are further considerations that might affect the memory use or performance of your solution then do make a note of them.

Some sample data is provided below for you to use when testing your solution. The first line contains an integer n denoting the number of boxes. The next n lines contain the four floating point values a, b, c, d that define Cartesian coordinates of the minimum corner and maximum corner of each box separated by a single space. Note that this input does not correspond to the above diagram.

14
1.0 1.0 10.0 6.0
1.5 1.5 6.0 5.0
2.0 2.0 3.0 3.0
2.0 3.5 3.0 4.5
3.5 2.0 5.5 4.5
4.0 3.5 5.0 4.0
4.0 2.5 5.0 3.0
7.0 3.0 9.5 5.5
7.5 4.0 8.0 5.0
8.5 3.5 9.0 4.5
3.0 7.0 8.0 10.0
5.0 7.5 7.5 9.5
5.5 8.0 6.0 9.0
6.5 8.0 7.0 9.0

9

To display the output graphically you need to have turtle library.

NOTE! If you just want to see the output on the console ignore installing turtle

We need to install Python-3 (not Python-2)

Linux operating system, e.g. Ubuntu and Mint, have pre-installed Python-3, but it may not contain turtle library. To install the turtle library, use following command:

$ sudo apt-get install python3-tk

usage: 
  main.py [-h] [-r READER] -a READER_ARGS [READER_ARGS ...] [-op OUTPUT_TYPE] [-z ZOOM_LEVEL]

optional arguments:
  -h, --help            show this help message and exit

output options:
  -op OUTPUT_TYPE, --output OUTPUT_TYPE
                        Display the result to user additional to the stdout.
                        Currently only 'TurtleGraphic' available (Default
                        None)

  -z ZOOM_LEVEL, --zoom ZOOM_LEVEL
                        Zoom level if -op is set to 'TurtleGraphic' (Default
                        25)

input options:
  -r READER, --reader READER
                        Input type to read data from (default 'readfile')
  
  -a READER_ARGS [READER_ARGS ...], --arguments READER_ARGS [READER_ARGS ...]
                        Arguments to be passed to the reader defined in -r
                        option

    python -a <path/to/coordinates/file> -op TurtleGraphic -z 25

    python -a <path/to/coordinates/file>