Codeforces Round 865 (Div. 1)
E
Bosco and Particle
Codeforces
3100
原题
← DF →
翻译中…

Bosco is studying the behaviour of particles. He decided to investigate on the peculiar behaviour of the so-called "four-one-two" particle. He does the following:

翻译中…

There is a line of length $n+1$, where the topmost point is position $0$ and bottommost is position $n+1$. The particle is initially (at time $t=0$) at position $0$ and heading downwards. The particle moves at the speed of $1$ unit per second. There are $n$ oscillators at positions $1,2,\ldots,n$.

翻译中…

Each oscillator can be described by a binary string. The initial state of each oscillator is the first character of its binary string. When the particle hits with an oscillator, the particle reverses its direction if its current state is $\texttt{1}$ and continues to move at the same direction if its current state is $\texttt{0}$, and that oscillator moves on to the next state (the next state of the last state is defined as the first state). Additionally, the particle always reverses its direction when it is at position $0$ or $n+1$ at time $t \gt 0$.

翻译中…

Bosco would like to know the cycle length of the movement of particle. The cycle length is defined as the minimum value of $c$ such that for any time $t \ge 0$, the position of the particle at time $t$ is same as the position of the particle at time $t+c$. It can be proved that such value $c$ always exists. As he realises the answer might be too large, he asks you to output your answer modulo $998244353$.

翻译中…

Input

翻译中…

The first line contains an integer $n$ ($1\le n\le10^6$) — the number of oscillators.

翻译中…

The $i$-th of the next $n$ line contains a binary string $s_i$ ($1\le\left|s_i\right|\le10^6$) — the binary string, that contains only characters $\texttt{0}$ and $\texttt{1}$, describing the oscillator at position $i$.

翻译中…

It is guaranteed that the sum of all $|s_i|$ does not exceed $10^6$.

翻译中…

Output

翻译中…

Output a single integer integer — the cycle length of the movement of the particle, modulo $998244353$.

翻译中…

Note

翻译中…

In the first sample, the only oscillator at position $1$ always has state $\texttt{0}$. At time moments $0,1,2,3$ positions the particle are $0,1,2,1$ respectively. Then the same positions will be repeated, so $c=4$.

翻译中…

Animation for the second sample: here or a smoother animation.

翻译中…

样例

Input #1
1
00
Output #1
4
InputCopy OutputCopy
Input #2
2
01
010
Output #2
16
InputCopy OutputCopy
Input #3
4
0101
000
1
01
Output #3
12
InputCopy OutputCopy
Input #4
4
01010
0001
11
0001
Output #4
120
InputCopy OutputCopy
题目信息
题号
1815E
时间限制
2 s
内存限制
256 MB
标签
动态规划
数学
数论
字符串

题面与样例版权归 Codeforces 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。