feat(codeforces): more div3 as

codeforces/988/a.cc

@@ -0,0 +1,71 @@
+#include <bits/stdc++.h> // {{{
+
+#include <version>
+#ifdef __cpp_lib_ranges_enumerate
+#include <ranges>
+namespace rv = std::views;
+namespace rs = std::ranges;
+#endif
+
+#pragma GCC optimize("O2,unroll-loops")
+#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
+
+using namespace std;
+
+using i16 = int16_t;
+using u16 = uint16_t;
+using i32 = int32_t;
+using u32 = uint32_t;
+using i64 = int64_t;
+using u64 = uint64_t;
+using f64 = double;
+using f128 = long double;
+
+#if __cplusplus >= 202002L
+template <typename T> constexpr T MIN = std::numeric_limits<T>::min();
+
+template <typename T> constexpr T MAX = std::numeric_limits<T>::max();
+#endif
+
+#ifdef LOCAL
+#define db(...) std::print(__VA_ARGS__)
+#define dbln(...) std::println(__VA_ARGS__)
+#else
+#define db(...)
+#define dbln(...)
+#endif
+//  }}}
+
+vector<u32> f(21);
+void solve() {
+    u32 n;
+    cin >> n;
+    f.assign(f.size(), 0);
+    u32 a;
+    for (u32 i = 0; i < n; ++i) {
+        cin >> a;
+        ++f[a];
+    }
+
+    println("{}", accumulate(begin(f), end(f), 0, [](auto acc, auto x) {
+                return acc + x / 2;
+            }));
+}
+
+int main() { // {{{
+    std::cin.exceptions(std::cin.failbit);
+#ifdef LOCAL
+    std::cerr.rdbuf(std::cout.rdbuf());
+    std::cout.setf(std::ios::unitbuf);
+    std::cerr.setf(std::ios::unitbuf);
+#else
+    std::cin.tie(nullptr)->sync_with_stdio(false);
+#endif
+    u32 tc = 1;
+    std::cin >> tc;
+    for (u32 t = 0; t < tc; ++t) {
+        solve();
+    }
+    return 0;
+}
+// }}}