- 题目提供者 FarmerJohn2
- 评测方式 云端评测
- 标签 USACO 2013 高性能
- 难度 提高+/省选-
- 时空限制 1000ms / 128MB
Farmer John is taking Bessie and the cows on a cruise! They are sailing on a network of rivers with N ports (1 <= N <= 1,000) labeled 1..N, and Bessie starts at port 1. Each port has exactly two rivers leading out of it which lead directly to other ports, and rivers can only be sailed one way.
At each port, the tour guides choose either the "left" river or the "right" river to sail down next, but they keep repeating the same choices over and over. More specifically, the tour guides have chosen a short sequence of M directions (1 <= M <= 500), each either "left" or "right", and have repeated it K times (1 <= K <= 1,000,000,000). Bessie thinks she is going in circles -- help her figure out where she ends up!
在每一个港口，导游选择左边的河或右边的河向下航行，但他们不断重复相同的选择一遍又一遍。更具体地说，导游选择了一个m方向（1 < =m= 500），每一个向左或向右，并重复它K次（1 < = K = 1000000000）。Bessie认为她是在兜圈子，帮她找出结束的位置！
* Line 1: Three space-separated integers N, M, and K.
* Lines 2..N+1: Line i+1 has two space-separated integers,
representing the number of the ports that port i's left and right rivers lead to, respectively.
* Line N+2: M space-separated characters, either 'L' or 'R'. 'L' represents a choice of 'left' and 'R' represents a choice of 'right'.输出格式：
* Line 1: A single integer giving the number of the port where Bessie's cruise ends.
The port numbers are arranged clockwise in a circle, with 'L' being a clockwise rotation and 'R' being a counterclockwise rotation. The sequence taken is LLRLLRLLR.
After the first iteration of the sequence of directions, Bessie is at port 2 (1 -> 2 -> 3 -> 2); after the second, she is at port 3 (2 -> 3 -> 4 -> 3), and at the end she is at port 4 (3 -> 4 -> 1 -> 4).
感谢 @ SilverWolf 提供翻译