cp/codeforces/799/b.cc

54 lines
929 B
C++

#include <bits/stdc++.h> // {{{
// https://codeforces.com/blog/entry/96344
#pragma GCC optimize("O2,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
using namespace std;
#define prln(...) std::println(__VA_ARGS__)
#define pr(...) std::print(__VA_ARGS__)
#ifdef LOCAL
#define dbgln(...) std::println(__VA_ARGS__)
#define dbg(...) std::print(__VA_ARGS__)
#else
#define dbgln(...)
#define dbg(...)
#endif
// }}}
bitset<10000 + 1> seen;
void solve() {
seen.reset();
int n;
cin >> n;
int a, dups = 0;
for (int i = 0; i < n; ++i) {
cin >> a;
if (seen[a]) {
++dups;
} else {
seen[a] = true;
}
}
int unique = n - dups;
cout << (dups & 1 ? unique - 1 : unique) << '\n';
}
int main() { // {{{
cin.tie(nullptr)->sync_with_stdio(false);
cin.exceptions(cin.failbit);
int tc = 1;
cin >> tc;
for (int t = 0; t < tc; ++t) {
solve();
}
return 0;
}
// }}}