AtCoder Grand Contest 063
A
Mex Game
AtCoder
⌀ 952
原题
←B →
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Problem Statement

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You are given a string of length $N+1$ consisting of A and B: $S = S_0\cdots S_N$. For each $k=1, \ldots, N$, solve the following problem.

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Alice and Bob will play a game using a set $X$, which is initially empty. For $t=1,\ldots, k$ in this order, they will do the following action:

  • if $t$ is odd, Alice will choose a non-negative integer $x$ and replace $X$ with $X\cup \{x\}$;
  • if $t$ is even, Bob will choose a non-negative integer $x$ and replace $X$ with $X\cup \{x\}$.

Let $x$ be $\mathrm{mex}(X)$ after all $k$ actions. If the character $S_x$ is A, Alice wins; if $S_x$ is B, Bob wins. Note that $X$ has at most $k$ elements, so $x = \mathrm{mex}(X) \leq k$ and the character $S_x$ exists.

Print the name of the winner when both players play optimally.

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What is $\mathrm{mex}(X)$? For a finite set $X$ consisting of non-negative integers, $\mathrm{mex}(X)$ is the smallest non-negative integer $x$ such that $x\notin X$.

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Constraints

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  • $1\leq N\leq 2\times 10^5$
  • $S$ is a string of length $N+1$ consisting of A and B.
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Input

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The input is given from Standard Input in the following format:

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N
S

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Output

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Print $N$ lines. The $i$-th line should contain the winner's name (Alice or Bob) when both players play optimally in the game with $k=i$.

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样例

Input #1
2
ABB
Output #1
Alice
Bob
Here is a possible progression of the game with $k=1$. - Alice chooses $x=10$. - $\mathrm{mex}(X)=\mathrm{mex}(\lbrace 10\rbrace) = 0$, and $S_0$ is `A`, so Alice wins. Here is a possible progression of the game with $k=2$. - Alice chooses $x=2$. - Bob chooses $x=0$. - $\mathrm{mex}(X)=\mathrm{mex}(\lbrace 0,2\rbrace) = 1$, and $S_1$ is `B`, so Bob wins.
Input #2
4
AAAAA
Output #2
Alice
Alice
Alice
Alice
Input #3
7
BBAABABA
Output #3
Bob
Bob
Alice
Bob
Alice
Bob
Alice
题目信息
题号
agc063_a
时间限制
2 s
内存限制
1024 MB

题面与样例版权归 AtCoder 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。