c++数组去重并打印

以下是一种C++数组去重并打印的方法：

#include <iostream>
#include <unordered_set>
using namespace std;

int main() {
    int n;
    cin >> n;
    int arr[n];
    for (int i = 0; i < n; i++) {
        cin >> arr[i];
    }
    
    unordered_set<int> uniqueElements;
    for (int i = n - 1; i >= 0; i--) {
        if (uniqueElements.find(arr[i]) == uniqueElements.end()) {
            uniqueElements.insert(arr[i]);
        }
    }
    
    cout << uniqueElements.size() << endl;
    for (auto it = uniqueElements.begin(); it != uniqueElements.end(); it++) {
        cout << *it << " ";
    }
    cout << endl;
    
    return 0;
}