总结一下追及问题。（UVA12791） 
注：我一开始没看见要求的是快车手所在的圈数，爆了几次 Wrong Answer 才反应过来。所以才有这篇总结。 
原题面： 

[!abstract] 
Problem Statement: 
In motorsports, it is very common that the leader pilot in a race, at a certain moment, overtakes the last pilot. The leader, at this moment, is one lap ahead of the last pilot, who then becomes a straggler. In this task, given the time it takes for the fastest pilot and for the sl...