P22050 [CodeChef] BINARYSUB
提高-
题目描述

Chef has a binary string S. He can replace any occurrence of -
- 01 with a
- 10 with b
- 010 with ab
- 101 with ba

While doing these operations, Chef noticed that he can end up with different strings depending upon the order of application of the operations. Given the final string containing only a and b, Chef wants to know the number of possible strings he might have began with.

As the number of initial strings can be large, print the result modulo 998244353.

------ Input Format ------

  • The first line of input will contain a single integer T, denoting the number of test cases.
  • Each test case consists of a single line of input denoting S, the final string obtained after applying the operations.

------ Output Format ------

For each test case, output the number of original strings that can result in the final string mod 998244353.

------ Constraints ------

$1 ≤ T ≤ 5\cdot 10^{4}$
$1 ≤ |S| ≤ 10^{5}$
- The sum of $|S|$ over all test cases won't exceed $5\cdot 10^{5}$.
$S$ consists of $a$ and $b$ only.

----- Sample Input 1 ------
3
ab
aa
abb

----- Sample Output 1 ------
2
1
2

----- explanation 1 ------
Test case $1$: The binary strings that can result in the string $ab$ are $0110$ and $010$.
- $0110$: Replace the first two characters $01$ with $a$ and last two characters $10$ with $b$. Thus, we get $ab$.
- $010$: Replace the characters $010$ with $ab$.

Test case $2$: The only binary string that can result in the string $aa$ is $0101$. In $0101$, we replace the first two characters with $a$ and last two characters with $a$ as well.

Test case $3$: The binary strings that can result in the string $abb$ are $011010$ and $01010$.
- $011010$: Replace the first two characters $01$ with $a$, next two characters $10$ with $b$, and last two characters $10$ with $b$. Thus, we get $abb$.
- $01010$: Replace the characters $010$ with $ab$ and the characters $10$ with $b$.

输入格式

见题面

输出格式

见题面

样例输入
3 ab aa abb
样例输出
2 1 2