Monotone Subsequence

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문제

This is an interactive problem.

Faker is being naughty again. You asked him to create a nice query problem, but he created an interactive problem where he is answering a query instead! Faker hid a permutation from you, and you have to infer some interesting information by interacting with him.

You are given an integer $n$. Faker hid a hidden permutation* $p_1, p_2, \ldots, p_{n^2+1}$ of length $n^2+1$. Your goal is to find a monotone subsequence (either increasing or decreasing) of the hidden permutation, with length exactly $n+1$. It can be proved that every permutation of length $n^2 + 1$ contains a monotone subsequence of length $n+1$. For more information about the proof, you can check out this Wikipedia page.

To find it, you can make at most $n$ skyscraper queries to the interactor, which is defined as follows:

  • You provide a set of $k$ indices as a strictly increasing sequence: $i_1, i_2, \ldots, i_k$.
  • The interactor considers the values of the hidden permutation at these indices: $p_{i_1}, p_{i_2}, \ldots, p_{i_k}$.
  • The interactor then returns the indices corresponding to the visible skyscrapers from this set. An index $i_j$ is visible if its value $p_{i_j}$ is greater than the values of all preceding elements in your query, i.e., $p_{i_j} > p_{i_m}$ for all $1 \le m < j$. This is equivalent to finding the indices of the left-to-right maxima of the sequence $(p_{i_1}, \ldots, p_{i_k})$.

After making at most $n$ queries, you must report a valid monotone subsequence of length exactly $n+1$.

Note that the permutation $p$ is fixed before any queries are made and does not depend on the queries.


*A permutation of length $m$ is an array consisting of $m$ distinct integers from $1$ to $m$ in arbitrary order. For example, $[2,3,1,5,4]$ is a permutation, but $[1,2,2]$ is not a permutation ($2$ appears twice in the array), and $[1,3,4]$ is also not a permutation ($m=3$ but there is $4$ in the array).

입력

Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 5000$). The description of the test cases follows.

The first and only line of each test case contains a single integer $n$ ($1 \le n \le 100$).

It is guaranteed that the sum of $n^2+1$ over all test cases does not exceed $10\,001$.

힌트

For the first test case, $n=1$. The hidden permutation is $p=[1, 2]$.

  • For the query ? 2 1 2, the visible skyscrapers are at indices $1$ and $2$. The interactor returns 2 1 2.
  • An increasing subsequence of length $2$ at indices $1, 2$ is reported.

For the second test case, $n=2$. The hidden permutation is $p=[5, 3, 4, 1, 2]$.

  • For the query ? 3 1 2 3, the visible skyscraper is at index $1$. The interactor returns 1 1.
  • For the query ? 3 2 3 5, the visible skyscrapers are at indices $2$ and $3$. The interactor returns 2 2 3.
  • A decreasing subsequence of length $3$ at indices $1, 3, 4$ is reported.

Although Faker will play the role of interactor, the interactor will never lie to you.