Tractor Paths
문제
Farmer John has () tractors, where the th tractor can only be used within the inclusive interval . The tractor intervals have left endpoints and right endpoints . Some of the tractors are special.
Two tractors and are said to be adjacent if and intersect. Farmer John can transfer from one tractor to any adjacent tractor. A path between two tractors and consists of a sequence of transfers such that the first tractor in the sequence is , the last tractor in the sequence is , and every two consecutive tractors in the sequence are adjacent. It is guaranteed that there is a path between tractor and tractor . The length of a path is the number of transfers (or equivalently, the number of tractors within it minus one).
You are given () queries, each specifying a pair of tractors and (). For each query, output two integers:
- The length of any shortest path between tractor to tractor .
- The number of special tractors such that there exists at least one shortest path from tractor to tractor containing it.
입력
The first line contains and .
The next line contains a string of length consisting of Ls and Rs, representing the left and right endpoints in sorted order. It is guaranteed that for each proper prefix of this string, the number of Ls exceeds the number of Rs.
The next line contains a bit string of length , representing for each tractor whether it is special or not.
The next lines each contain two integers and , specifying a query.
출력
For each query, the two quantities separated by spaces.
힌트
The tractor intervals, in order, are .
For the th query, there are three shortest paths between the st and th tractor: to to , to to , and to to . These shortest paths all have length .
Additionally, every tractor is part of one of the three shortest paths mentioned earlier, and since are special, there are special tractors such that there exists at least one shortest path from tractor to containing it.
예제
예제 1
8 10 LLLLRLLLLRRRRRRR 11011010 1 2 1 3 1 4 1 5 1 6 1 7 1 8 2 3 2 4 2 5
1 2 1 1 1 2 2 4 2 3 2 4 2 3 1 1 1 2 1 2