P7680 [CF1628A] Meximum Array
普及
题目描述

Mihai has just learned about the MEX concept and since he liked it so much, he decided to use it right away.

Given an array $a$ of $n$ non-negative integers, Mihai wants to create a new array $b$ that is formed in the following way:

While $a$ is not empty:

  • Choose an integer $k$ ($1 \leq k \leq |a|$).
  • Append the MEX of the first $k$ numbers of the array $a$ to the end of array $b$ and erase them from the array $a$, shifting the positions of the remaining numbers in $a$.

But, since Mihai loves big arrays as much as the MEX concept, he wants the new array $b$ to be the lexicographically maximum. So, Mihai asks you to tell him what the maximum array $b$ that can be created by constructing the array optimally is.

An array $x$ is lexicographically greater than an array $y$ if in the first position where $x$ and $y$ differ $x_i > y_i$ or if $|x| > |y|$ and $y$ is a prefix of $x$ (where $|x|$ denotes the size of the array $x$).

The MEX of a set of non-negative integers is the minimal non-negative integer such that it is not in the set. For example, MEX({${1, 2, 3}$}) $= 0$ and MEX({${0, 1, 2, 4, 5}$}) $= 3$.

Input

The first line of the input contains a single integer $t$ ($1 \le t \le 100$) — the number of test cases. The description of test cases follows.

The first line of each test case contains a single integer $n$ ($1 \leq n \leq 2 \cdot 10^5$) — the number of elements in the array $a$.

The second line of each test case contains $n$ non-negative integers $a_1, \ldots, a_n$ ($0 \leq a_i \leq n$), where $a_i$ is the $i$-th integer from the array $a$.

It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

Output

For each test case print $m$ — the length of the maximum array $b$ Mihai can create, followed by $m$ integers denoting the elements of the array $b$.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
6 5 1 0 2 0 3 8 2 2 3 4 0 1 2 0 1 1 5 0 1 2 3 4 4 0 1 1 0 10 0 0 2 1 1 1 0 0 1 1
样例输出
1 4 2 5 1 1 0 1 5 2 2 2 4 3 2 2 0
提示

In the first test case, the lexicographically maximum array $b$ is obtained by selecting $k=5$, resulting in the $MEX$ of the whole array $a$. It is lexicographically maximum because an array starting with a smaller number than $4$ is lexicographically smaller, and choosing a $k<5$ would result in an array starting with a number smaller than $4$.

In the second test case, there are two ways to obtain the maximum array: first selecting $k=6$, then $k=2$, or first selecting $k=7$ and then $k=1$.