Problem Statement
Given is a sequence $p$ which is a permutation of $(1,2, \ldots, N)$. Initially, the $n$-th term of $p$ is $p_{n}$.
Your objective is to sort $p$ in ascending order in at most $N^2$ operations. In one operation, you make the following change on $p$:
- In the
$1$-st,$3$-rd, and subsequent odd-numbered operations, you choose an odd number$n$between$1$and$N-1$(inclusive) to swap$p_n$and$p_{n+1}$. - In the
$2$-nd,$4$-th, and subsequent even-numbered operations, you choose an even number$n$between$2$and$N-1$(inclusive) to swap$p_n$and$p_{n+1}$.
We can prove that the objective is always achievable under the Constraints of this problem. Find one sequence of operations that achieves the objective.
You will be given $T$ test cases and asked to solve each of them.
Constraints
- All values in input are integers.
$1 \leq T \leq 250$$2 \leq N \leq 500$$1 \leq p_i \leq N$$p$is a permutation of$(1,2,\ldots,N)$.- In one input file, the sum of
$N$does not exceed$500$.
Input
Input is given from Standard Input in the following format:
T
\mathrm{case}_{1}
\vdots
\mathrm{case}_{T}
Each case is in the following format:
N
p_1 \cdots p_N
Output
For each of the $T$ test cases, in the order they are given, print your answer in the following format:
M
a_1 \cdots a_M
Here, $M$ represents the length of your sequence of operations, and $a_i$ represents the integer you choose in the $i$-th operation.
Your output will be considered correct if, for every test case, your sequence of operations achieves the objective.
样例
2
5
2 1 3 5 4
2
1 2
2
1 4
0
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