Last week, there was a preliminary ICPC contest in Korea, whose result is used to select teams from various universities to advance to the Seoul Regional (regional contest in Korea)
This is the problemset: http://icpckorea.org/2018/preliminary/problems.pdf
Most problems were solved, at least algorithmically, by people during the contest or after the contest. However, anyone, including some top-tier people in our country, couldn't solve problem C.
In the contest, problem C was solved, but it was just because the test data was super weak to allow solutions with complexity O(n2 / k) :p Since the description is short enough, I will not describe the problem here, just click the link to see the task.
I am really curious about the solution of this problem. Could I get some hints about this task? Thanks in advance :)
