A845.COW Operations--Silver

普及+/提高

USACO

通过率:0%

时间限制:1.00s

内存限制:128MB

题目描述

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.

输入格式

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).

输出格式

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

输入输出样例

  • 输入#1

    COW
    6
    1 1
    1 2
    1 3
    2 2
    2 3
    3 3
    

    输出#1

    YNNNYN
    

说明/提示

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'

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