P24928 [AtCoder] Mex Game
普及
题目描述

Problem Statement

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.

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.

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 $x\notin X$.

Input

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

Output

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.

Constraints

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

Sample Input 1

2
ABB

Sample 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.

Sample Input 2

4
AAAAA

Sample Output 2

Alice
Alice
Alice
Alice

Sample Input 3

7
BBAABABA

Sample Output 3

Bob
Bob
Alice
Bob
Alice
Bob
Alice

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
2 ABB
样例输出
Alice Bob