PivotOJ

COW Operations

시간 제한: 2000ms메모리 제한: 1024MB출처: USACO 2022 Open SilverBOJ 24979

문제

Bessie finds a string ss of length at most 21052 \cdot 10^5 containing only the three characters 'C', 'O', and 'W'. She wants to know if it's possible to turn this string into a single 'C' (her favorite letter) using the following operations:

1. Choose two adjacent equal letters and delete them.

2. Choose one letter and replace it with the other two letters in either order.

Finding the answer on the string itself isn't enough for Bessie, so she wants to know the answer for QQ (1Q21051\le Q\le 2\cdot 10^5) substrings of ss.

입력

The first line contains ss.

The next line contains QQ.

The next QQ lines each contain two integers ll and rr (1lrs1\le l\le r\le |s|, where s|s| denotes the length of ss).

출력

A string of length QQ, with the ii-th character being 'Y' if the ii-th substring can be reduced and 'N' otherwise.

힌트

The answer to the first query is yes because the first character of ss is already equal to 'C'.

The answer to the fifth query is yes because the substring OW from the second to the third character of ss can be converted into 'C' in two operations:

   OW
-> CWW
-> C

No other substring of this example string COW can be reduced to 'C'

예제

예제 1

입력
COW
6
1 1
1 2
1 3
2 2
2 3
3 3
출력
YNNNYN
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