[CODEFORCES] ROUND #656 (DIV. 3) B

cf_656_b.cpp

#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
 
bool chk[51];
 
int main() {
 
    cin.tie(nullptr);
    cout.tie(NULL);
    ios_base::sync_with_stdio(false);
 
    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        vector<int> ans;
        for (int i = 0; i < 2 * n; i++) {
            int tmp;
            cin >> tmp;
            if (!chk[tmp]) {
                ans.push_back(tmp);
                chk[tmp] = true;
            }
        }
        for (int i = 0; i < ans.size(); i++)
            cout << ans[i] << " ";
        cout << '\n';
 
        memset(chk, false, sizeof(chk));
    }
 
    return 0;
}