Description

• Your program reads one text file:
  • txt
• Your program creates a text file:
  • txt
• Your program solves the following problem:
  • You are given a water level information L. Condition: 0<L<
  • You are given a terrain information (elevation matrix M). Condition: 0≤M[i][j]<128∀i,j<
  • Calculate how many islands are formed and return a coordinate value for each island.
  • Definition of an island: An island is the collection of terrain points( elevation values M[i][j]), above water( greater than L value), from which you can find a path to any other without having to pass the path through water.
  • Definition of a path: A path is an ordered set of points where successive points have either their X coordinates the same and their Y coordinates different only by one in magnitude (so can be y – 1 or y + 1); or have their Y coordinates the same and have their X coordinates different only by one in magnitude (so can be x – 1 or x + 1). But not both of them: in other words they have to touch either in the X direction or in the Y direction, and not in the diagonal.
  • If a piece of terrain is partially (or fully) located (touching) at the edge(s) of the 512 × 512 grid, still it will count as an island.

input.txt

• First line is a single integer. (The L value)
• The rest of the file has 262144 integers. Skip all the whitespace and read all of these integers and create a 512×512 matrix. Integers are listed in row-order.

output.txt

• The first line is an integer (number of islands)
• Each line after the first line holds coordinate information of a point on an island. (single point for each island)
• Example: Here there are 5 islands. (#… are comments, which are not printed.)

5
x_coordinate1 y_coordinate1	#coordinate of a point which is on island1
x_coordinate2 y_coordinate2	#coordinate of a point which is on island2
x_coordinate3 y_coordinate3	#coordinate of a point which is on island3
x_coordinate4 y_coordinate4	#coordinate of a point which is on island4
x_coordinate5 y_coordinate5	#coordinate of a point which is on island5

Remarks

• There will be at most 100 islands.
• You can allocate only one array.(create an array for the terrain data).
• You cannot declare any other array in your program.
• You cannot use dynamic allocation.
• Do not submit your code without testing it with several different scenarios.
• Write comments in your code.
• Do not print anything to stdout and stderr.
• Do not submit any of the files you used for testing.
• Do not submit your output file.

Turn in:

• Source code of a complete C program. Name of the file should be in this format: <full_name>_<id>.c.
• Example: gokhan_kaya_000000.c. Please do not use any Turkish special characters.
• You don’t need to use an IDE for this assignment. Your code will be compiled and run in a command window.
• Your code will be compiled and tested on a Linux machine(Ubuntu). GCC will be used.
• Make sure you don’t get compile errors when you issue this command : gcc <full_name>_<id>.c.
• A script will be used in order to check the correctness of your results. So, be careful not to violate the expected output format.
• Provide comments unless you are not interested in partial credit. (If I cannot easily understand your design, you may loose points.)

You may not get full credit if your implementation contradicts with the statements in this document.