Codeforces Round 467 (Div. 1)
C
Lock Puzzle
Codeforces
2300
原题
← BD →
翻译中…

Welcome to another task about breaking the code lock! Explorers Whitfield and Martin came across an unusual safe, inside of which, according to rumors, there are untold riches, among which one can find the solution of the problem of discrete logarithm!

翻译中…

Of course, there is a code lock is installed on the safe. The lock has a screen that displays a string of $*n*$ lowercase Latin letters. Initially, the screen displays string $*s*$. Whitfield and Martin found out that the safe will open when string $*t*$ will be displayed on the screen.

翻译中…

The string on the screen can be changed using the operation «shift $*x*$». In order to apply this operation, explorers choose an integer $*x*$ from 0 to $*n*$ inclusive. After that, the current string $*p* = αβ$ changes to $β^{*R*}α$, where the length of $β$ is $*x*$, and the length of $α$ is $*n* - *x*$. In other words, the suffix of the length $*x*$ of string $*p*$ is reversed and moved to the beginning of the string. For example, after the operation «shift $4$» the string «abcacb» will be changed with string «bcacab », since $α =$ab, $β =$cacb, $β^{*R*} =$bcac.

翻译中…

Explorers are afraid that if they apply too many operations «shift», the lock will be locked forever. They ask you to find a way to get the string $*t*$ on the screen, using no more than $6100$ operations.

翻译中…

Input

翻译中…

The first line contains an integer $*n*$, the length of the strings $*s*$ and $*t*$ ($1 ≤ *n* ≤ 2 000$).

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After that, there are two strings $*s*$ and $*t*$, consisting of $*n*$ lowercase Latin letters each.

翻译中…

Output

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If it is impossible to get string $*t*$ from string $*s*$ using no more than 6100 operations «shift», print a single number $- 1$.

翻译中…

Otherwise, in the first line output the number of operations $*k*$ ($0 ≤ *k* ≤ 6100$). In the next line output $*k*$ numbers $*x*_{*i*}$ corresponding to the operations «shift $*x*_{*i*}$» ($0 ≤ *x*_{*i*} ≤ *n*$) in the order in which they should be applied.

翻译中…

样例

Input #1
6
abacbb
babcba
Output #1
4
6 3 2 3
InputCopy OutputCopy
Input #2
3
aba
bba
Output #2
-1
InputCopy OutputCopy
题目信息
题号
936C
时间限制
2 s
内存限制
256 MB
标签
构造
模拟
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。