Files
contests/misc/tlbdhsg/b19.cpp

26 lines
393 B
C++

#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
cin >> n;
unordered_set<int> hash;
deque<int> res;
while (n--) {
int x;
cin >> x;
if (hash.find(x) == hash.end()) {
res.push_back(x);
hash.insert(x);
}
}
cout << res.size() << '\n';
while (!res.empty()) {
cout << res.front() << " ";
res.pop_front();
}
cout << '\n';
}