王 · 发布于 2025-10-12 · 浏览 266 回复 0

int n;
cin >> n;
unordered_set<int>c;
for (int i = 0; i < n; ++i) {
	int k;
	cin >> k;
	c.insert(k);
}
cout << min(int(c.size()), n / 2);
return 0;