用set去重，用list排序。

//C++版代码
#include <iostream>
#include <vector>
#include <unordered_set>
#include <algorithm>
using namespace std;
int main() {
    int n;
    unordered_set<int> nums;
    cin >> n;
    while (n--) {
        int num;
        cin >> num;
        nums.insert(num);
    }
    vector<int> ans(nums.begin(), nums.end());
    sort(ans.begin(), ans.end());
    for (int num: ans) {
        cout << num << " ";
    }
    return 0;
}
//Java版代码
import java.util.Arrays;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Set<Integer> set = new HashSet<>();
        while (n-- != 0) {
            set.add(sc.nextInt());
        }
        set.stream().sorted().forEach(num -> System.out.print(num + " "));
    }
}
#Python版代码
input()
print(*sorted(set(map(int, input().split()))))