You are given a deck of $n$ cards numbered from $1$ to $n$ (not necessarily in this order in the deck). You have to sort the deck by repeating the following operation.
- Choose
$2 \le k \le n$and split the deck in$k$nonempty contiguous parts$D_1, D_2,\dots, D_k$($D_1$contains the first$|D_1|$cards of the deck,$D_2$contains the following$|D_2|$cards and so on). Then reverse the order of the parts, transforming the deck into$D_k, D_{k-1}, \dots, D_2, D_1$(so, the first$|D_k|$cards of the new deck are$D_k$, the following$|D_{k-1}|$cards are$D_{k-1}$and so on). The internal order of each packet of cards$D_i$is unchanged by the operation.
You have to obtain a sorted deck (i.e., a deck where the first card is $1$, the second is $2$ and so on) performing at most $n$ operations. It can be proven that it is always possible to sort the deck performing at most $n$ operations.
Examples of operation: The following are three examples of valid operations (on three decks with different sizes).
- If the deck is
[3 6 2 1 4 5 7](so$3$is the first card and$7$is the last card), we may apply the operation with$k=4$and$D_1=$[3 6],$D_2=$[2 1 4],$D_3=$[5],$D_4=$[7]. Doing so, the deck becomes[7 5 2 1 4 3 6]. - If the deck is
[3 1 2], we may apply the operation with$k=3$and$D_1=$[3],$D_2=$[1],$D_3=$[2]. Doing so, the deck becomes[2 1 3]. - If the deck is
[5 1 2 4 3 6], we may apply the operation with$k=2$and$D_1=$[5 1],$D_2=$[2 4 3 6]. Doing so, the deck becomes[2 4 3 6 5 1].
Input
The first line of the input contains one integer $n$ ($1\le n\le 52$) — the number of cards in the deck.
The second line contains $n$ integers $c_1, c_2, \dots, c_n$ — the cards in the deck. The first card is $c_1$, the second is $c_2$ and so on.
It is guaranteed that for all $i=1,\dots,n$ there is exactly one $j\in\{1,\dots,n\}$ such that $c_j = i$.
Output
On the first line, print the number $q$ of operations you perform (it must hold $0\le q\le n$).
Then, print $q$ lines, each describing one operation.
To describe an operation, print on a single line the number $k$ of parts you are going to split the deck in, followed by the size of the $k$ parts: $|D_1|, |D_2|, \dots , |D_k|$.
It must hold $2\le k\le n$, and $|D_i|\ge 1$ for all $i=1,\dots,k$, and $|D_1|+|D_2|+\cdots + |D_k| = n$.
It can be proven that it is always possible to sort the deck performing at most $n$ operations. If there are several ways to sort the deck you can output any of them.
Note
Explanation of the first testcase: Initially the deck is [3 1 2 4].
- The first operation splits the deck as
[(3) (1 2) (4)]and then transforms it into[4 1 2 3]. - The second operation splits the deck as
[(4) (1 2 3)]and then transforms it into[1 2 3 4].
Explanation of the second testcase:
Initially the deck is
[6 5 4 3 2 1]
.
- The first (and only) operation splits the deck as
[(6) (5) (4) (3) (2) (1)]and then transforms it into[1 2 3 4 5 6].
样例
4
3 1 2 4
2
3 1 2 1
2 1 3
6
6 5 4 3 2 1
1
6 1 1 1 1 1 1
1
1
0
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。