Precreation contest files

misc/tlbdhsg/b19.cpp

@@ -0,0 +1,25 @@
+#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';
+}