I have got WA at 26 several times.
Is there something should i pay attention to ?
Thank you.

I had WA 26 when I used "cout << x...", but I've replaced it with "cout << setprecision(15) << x..." and it works.

Edited by author 15.09.2009 23:17

if you check angle=pi/2, don't use scalar product. and setprecision(10)