# Restore the Permutation by Merger Coding Question-Codeforces rated 800

# Problem Statement :

A permutation of length n is a sequence of integers from 11 to nn of length nn containing each number exactly once. For example, [1], [4,3,5,1,2], [3,2,1] are permutations, and [1,1], [0,1], [2,2,1,4] are not.

There was a permutation p[1…n]. It was merged with itself. In other words, let’s take two instances of p and insert elements of the second p into the first maintaining relative order of elements. The result is a sequence of the length 2n.

For example, if p=[3,1,2] some possible results are: [3,1,2,3,1,2], [3,3,1,1,2,2], [3,1,3,1,2,2]. The following sequences are not possible results of a merging: [1,3,2,1,2,3], [3,1,2,3,2,1], [3,3,1,2,2,1].

For example, if p=[2,1] the possible results are: [2,2,1,1], [2,1,2,1]. The following sequences are not possible results of a merging: [1,1,2,2], [2,1,1,2], [1,2,2,1].

Your task is to restore the permutation p by the given resulting sequence a. It is guaranteed that the answer

exists and is unique.You have to answer t independent test cases.

# Input Format:

The first line of the input contains one integer t (1≤t≤400) — the number of test cases. Then t test cases follow.

The first line of the test case contains one integer n (1≤n≤50) — the length of permutation. The second line of the test case contains 2n integers a1,a2,…,a2 (1≤ai≤n1≤ai≤n), where aiai is the ii-th element of aa. It is guaranteed that the array aa represents the result of merging of some permutation pp with the same permutation pp.

# Output Format:

For each test case, print the answer: n integers p1,p2,…,pn (1≤pi≤n), representing the initial permutation. It is guaranteed that the answer **exists and is unique**.

**Given:**

`5`

2

1 1 2 2

4

1 3 1 4 3 4 2 2

5

1 2 1 2 3 4 3 5 4 5

3

1 2 3 1 2 3

4

2 3 2 4 1 3 4 1

**Output:**

`1 2 `

1 3 4 2

1 2 3 4 5

1 2 3

2 3 4 1

# Explanation of given Test Cases :

`In the first case we see that the given sequence has been created by combining the array (1,2) twice.`