Chips on a Board

题意翻译

Alice 和 Bob 有一个 $n\times m$ 的棋盘。每行恰好有一个棋子。 他们以如下的方式进行一个游戏: - 选择一对整数 $l,r(1\leq l\leq r\leq m)$,将除第 $l\sim r$ 列之外的部分从棋盘上移除。 - 轮流进行操作,Alice 先手。每一次操作,玩家需要选择一个棋子,并将其向左走任意正整数步(不能移出棋盘)。第一个不能移动的玩家判负。 给定 $q$ 次独立的询问如 $L_i,R_i$ 所示,试求如果第一步中选择的整数是 $(L_i,R_i)$,谁会赢得游戏。 $1\leq n,m,q\leq 2\times 10^5$。

题目描述

Alice and Bob have a rectangular board consisting of $ n $ rows and $ m $ columns. Each row contains exactly one chip. Alice and Bob play the following game. They choose two integers $ l $ and $ r $ such that $ 1 \le l \le r \le m $ and cut the board in such a way that only the part of it between column $ l $ and column $ r $ (inclusive) remains. So, all columns to the left of column $ l $ and all columns to the right of column $ r $ no longer belong to the board. After cutting the board, they move chips on the remaining part of the board (the part from column $ l $ to column $ r $ ). They make alternating moves, and the player which cannot make a move loses the game. The first move is made by Alice, the second — by Bob, the third — by Alice, and so on. During their move, the player must choose one of the chips from the board and move it any positive number of cells to the left (so, if the chip was in column $ i $ , it can move to any column $ j < i $ , and the chips in the leftmost column cannot be chosen). Alice and Bob have $ q $ pairs of numbers $ L_i $ and $ R_i $ . For each such pair, they want to determine who will be the winner of the game if $ l = L_i $ and $ r = R_i $ . Note that these games should be considered independently (they don't affect the state of the board for the next games), and both Alice and Bob play optimally.

输入输出格式

输入格式


The first line contains two integers $ n $ and $ m $ ( $ 1 \le n, m \le 2 \cdot 10^5 $ ) — the number of rows and columns on the board, respectively. The second line contains $ n $ integers $ c_1, c_2, \dots, c_n $ ( $ 1 \le c_i \le m $ ), where $ c_i $ is the index of the column where the chip in the $ i $ -th row is located (so, the chip in the $ i $ -th row is in the $ c_i $ -th column). The third line contains one integer $ q $ ( $ 1 \le q \le 2 \cdot 10^5 $ ). Then $ q $ lines follow, the $ i $ -th of them contains two integers $ L_i $ and $ R_i $ ( $ 1 \le L_i \le R_i \le m $ ).

输出格式


Print a string of $ q $ characters. The $ i $ -th character should be A if Alice wins the game with $ l = L_i $ and $ r = R_i $ , or B if Bob wins it.

输入输出样例

输入样例 #1

8 10
1 3 3 7 4 2 6 9
7
2 3
1 3
1 4
1 10
5 10
8 10
9 10

输出样例 #1

BAAAAAB