题目描述
Permutation $p$ is a sequence of integers $p=[p_1, p_2, \dots, p_n]$, consisting of $n$ distinct (unique) positive integers between $1$ and $n$, inclusive. For example, the following sequences are permutations: $[3, 4, 1, 2]$, $[1]$, $[1, 2]$. The following sequences are not permutations: $[0]$, $[1, 2, 1]$, $[2, 3]$, $[0, 1, 2]$.
The important key is in the locked box that you need to open. To open the box you need to enter secret code. Secret code is a permutation $p$ of length $n$.
You don't know this permutation, you only know the array $q$ of prefix maximums of this permutation. Formally:
- $q_1=p_1$,
- $q_2=\max(p_1, p_2)$,
- $q_3=\max(p_1, p_2,p_3)$,
- ...
- $q_n=\max(p_1, p_2,\dots,p_n)$.
You want to construct any possible suitable permutation (i.e. any such permutation, that calculated $q$ for this permutation is equal to the given array).
Input
The first line contains integer number $t$ ($1 \le t \le 10^4$) — the number of test cases in the input. Then $t$ test cases follow.
The first line of a test case contains one integer $n$ $(1 \le n \le 10^{5})$ — the number of elements in the secret code permutation $p$.
The second line of a test case contains $n$ integers $q_1, q_2, \dots, q_n$ $(1 \le q_i \le n)$ — elements of the array $q$ for secret permutation. It is guaranteed that $q_i \le q_{i+1}$ for all $i$ ($1 \le i < n$).
The sum of all values $n$ over all the test cases in the input doesn't exceed $10^5$.
Output
For each test case, print:
- If it's impossible to find such a permutation $p$, print "-1" (without quotes).
- Otherwise, print $n$ distinct integers $p_1, p_2, \dots, p_n$ ($1 \le p_i \le n$). If there are multiple possible answers, you can print any of them.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the first test case of the example answer $[1,3,4,5,2]$ is the only possible answer:
- $q_{1} = p_{1} = 1$;
- $q_{2} = \max(p_{1}, p_{2}) = 3$;
- $q_{3} = \max(p_{1}, p_{2}, p_{3}) = 4$;
- $q_{4} = \max(p_{1}, p_{2}, p_{3}, p_{4}) = 5$;
- $q_{5} = \max(p_{1}, p_{2}, p_{3}, p_{4}, p_{5}) = 5$.
It can be proved that there are no answers for the second test case of the example.