#include <iostream> #include <set> using namespace std; int main() { int numbers[] = {1, 2, 3, 2, 4, 5, 4}; set<int> seen; set<int> duplicates; for (int num : numbers) { if (seen.count(num)) { duplicates.insert(num); } else { seen.insert(num); } } cout << "Duplicates: "; for (int num : duplicates) { cout << num << " "; } return 0; }