My solution is geometrical, it passes all of my tests, except of one, where one side has a length of 0. But I got WA on test #2, so: 1) Can a polygon have a side with length of 0? 2) Can somebody give me any tests for this problem?
1) I'm pretty sure it can't, since otherwise my AC solution has a big chance to divide by zero. 2) 3 0 0 3 0 0 3 answer: 1.9308 Yeah, this is a pretty simple test but it actually helped me to overcome that WA #2.