Black Circles

Source: Codeforces 2002C

1. Read the problem and summarise the task requirements.
   • Try to keep your response to a couple of sentences.
2. Do some examples with pen and paper.
   • Hypothesise as to the strategy you should take to avoid the circles.
   • To prove it, think of the growing circles as the area that a predator can cover.

3. Design an algorithm to solve the problem.

4. Analyse the time complexity of your algorithm and estimate its running time.

5. Implement this algorithm in code.
   • Reflector:
     • What potential pitfalls can you think of?
     • Write some tests to check for these pitfalls.
   • Other group members:
     • Write a program which solves the problem.
   • Run your tests and debug if necessary.
6. Submit your program for judging!
   • Debug as required.