CircleUnionArea

Area of union of N circle

O( N^2 log N ): 그린 정리, https://math.stackexchange.com/questions/96839/area-of-union-of-n-circles O(N)도 가능하다는듯: https://stackoverflow.com/questions/1667310/combined-area-of-overlapping-circles 코포 글: https://codeforces.com/blog/entry/2111 문제: https://www.acmicpc.net/problem/17804