Hello, everyone.
Just wanted to summarize some info about this problem.
Ok, my code got AC with following things in it:
1. My pi was 3.1415926535897932384626433 (perhaps it is enough)
2. I used this formula from wikipedia
deltaArc=acos(sin(phiA)*sin(phiB)+cos(phiA)*cos(phiB)*cos(deltaL));
distance = deltaArc*3437.5;
(see the first formula from wikipedia http://en.wikipedia.org/wiki/Great-circle_distance)
3. I used the following condition:
if(100.00-distance>0.005) printf("DANGER!\n");
Hope it will help somebody.

thanks a lot ...your formula is really useful.^_^

Used everynth what is written here. However still WA8.
Any new ideas?...

kiitos

Thanks in advance!!

Thanks in advance!!

Thanks in advance!!

Thanx for your hint

Do u know that pi can be calculated by this formula: atan(1) * 4?