結果

問題 No.947 ABC包囲網
コンテスト
ユーザー Pachicobue
提出日時 2019-12-10 01:11:56
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 1,026 ms / 2,000 ms
コード長 5,922 bytes
コンパイル時間 2,360 ms
コンパイル使用メモリ 213,296 KB
最終ジャッジ日時 2025-01-08 10:20:32
ジャッジサーバーID
（参考情報） 		judge2 / judge4
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ファイルパターン 結果
other AC * 60
権限があれば一括ダウンロードができます

ソースコード

diff # 

#include <bits/stdc++.h>
// created [2019/12/10] 00:00:12
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-conversion"

using i32   = int32_t;
using i64   = int64_t;
using u32   = uint32_t;
using u64   = uint64_t;
using uint  = unsigned int;
using usize = std::size_t;
using ll    = long long;
using ull   = unsigned long long;
using ld    = long double;
template<typename T, usize n>
using arr = T (&)[n];
template<typename T, usize n>
using c_arr = const T (&)[n];
template<typename T> constexpr T popcount(const T u) { return u ? static_cast<T>(__builtin_popcountll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T log2p1(const T u) { return u ? static_cast<T>(64 - __builtin_clzll(static_cast<u64>(u))) : static_cast<T>(0); }
template<typename T> constexpr T msbp1(const T u) { return log2p1(u); }
template<typename T> constexpr T lsbp1(const T u) { return __builtin_ffsll(u); }
template<typename T> constexpr T clog(const T u) { return u ? log2p1(u - 1) : static_cast<T>(u); }
template<typename T> constexpr bool ispow2(const T u) { return u and (static_cast<u64>(u) & static_cast<u64>(u - 1)) == 0; }
template<typename T> constexpr T ceil2(const T u) { return static_cast<T>(1) << clog(u); }
template<typename T> constexpr T floor2(const T u) { return u == 0 ? static_cast<T>(0) : static_cast<T>(1) << (log2p1(u) - 1); }
template<typename T> constexpr bool btest(const T mask, const usize ind) { return static_cast<bool>((static_cast<u64>(mask) >> ind) & static_cast<u64>(1)); }
template<typename T> void bset(T& mask, const usize ind) { mask |= (static_cast<T>(1) << ind); }
template<typename T> void breset(T& mask, const usize ind) { mask &= ~(static_cast<T>(1) << ind); }
template<typename T> void bflip(T& mask, const usize ind) { mask ^= (static_cast<T>(1) << ind); }
template<typename T> void bset(T& mask, const usize ind, const bool b) { (b ? bset(mask, ind) : breset(mask, ind)); }
template<typename T> constexpr T bcut(const T mask, const usize ind) { return ind == 0 ? static_cast<T>(0) : static_cast<T>((static_cast<u64>(mask) << (64 - ind)) >> (64 - ind)); }
template<typename T> bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); }
template<typename T> bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); }
constexpr unsigned int mod                  = 1000000007;
template<typename T> constexpr T inf_v      = std::numeric_limits<T>::max() / 4;
template<typename Real> constexpr Real pi_v = Real{3.141592653589793238462643383279502884};

template<typename T>
T in()
{
    T v;
    return std::cin >> v, v;
}
template<typename T, typename Uint, usize n, usize i>
T in_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type) { return in<T>(); }
template<typename T, typename Uint, usize n, usize i>
auto in_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type& szs)
{
    const usize s = (usize)szs[i];
    std::vector<decltype(in_v<T, Uint, n, i + 1>(szs))> ans(s);
    for (usize j = 0; j < s; j++) { ans[j] = in_v<T, Uint, n, i + 1>(szs); }
    return ans;
}
template<typename T, typename Uint, usize n>
auto in_v(c_arr<Uint, n> szs) { return in_v<T, Uint, n, 0>(szs); }
template<typename... Types>
auto in_t() { return std::tuple<std::decay_t<Types>...>{in<Types>()...}; }
template<typename T>
void out(const T& v) { std::cout << v << '\n'; }  // Reactiveではstd::flushを忘れない
template<typename T, typename... Args>
void out(const T& v, const Args... args) { std::cout << v << ' ', out(args...); }
#    define SHOW(...) static_cast<void>(0)
constexpr ull TEN(const usize n) { return n == 0 ? 1ULL : TEN(n - 1) * 10ULL; }

template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i == n), c_arr<Uint, n>>::type, const T& v = T{}) { return v; }
template<typename T, typename Uint, usize n, usize i>
auto make_v(typename std::enable_if<(i < n), c_arr<Uint, n>>::type szs, const T& v = T{})
{
    const usize s = (usize)szs[i];
    return std::vector<decltype(make_v<T, n, i + 1>(szs, v))>(s, make_v<T, n, i + 1>(szs, v));
}
template<typename T, typename Uint, usize n>
auto make_v(c_arr<Uint, n> szs, const T& t = T{}) { return make_v<T, Uint, n, 0>(szs, t); }
int main()
{
    std::cin.tie(nullptr), std::ios::sync_with_stdio(false);
    int n = in<int>();
    std::vector<ll> xs, ys;
    for (int i = 0; i < n; i++) {
        const auto [x, y] = in_t<ll, ll>();
        if (x == 0 and y == 0) { continue; }
        xs.push_back(x), ys.push_back(y);
    }
    n = xs.size();
    struct Q
    {
        ll x, y;
    };
    struct C
    {
        bool operator()(const Q& q1, const Q& q2) const
        {
            auto pos = [](const ll x, const ll y) {  // 象限
                if (x >= 0 and y >= 0) { return 1; }
                if (x < 0 and y >= 0) { return 2; }
                if (x < 0 and y < 0) { return 3; }
                if (x >= 0 and y < 0) { return 4; }
                return 0;
            };
            const auto [x1, y1] = q1;
            const int p1        = pos(x1, y1);
            const auto [x2, y2] = q2;
            const int p2        = pos(x2, y2);
            if (p1 != p2) { return p1 < p2; }
            return y1 * x2 < y2 * x1;
        }
    };
    std::vector<Q> ss(n);
    for (int i = 0; i < n; i++) { ss[i] = {xs[i], ys[i]}; }
    std::sort(ss.begin(), ss.end(), C{});
    ll ans = 0;
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            Q si = ss[i], sj = ss[j];
            si.x *= -1LL, si.y *= -1LL;
            if (not C{}(si, sj) and not C{}(sj, si)) { continue; }
            sj.x *= -1LL, sj.y *= -1LL;
            std::tie(si, sj) = std::minmax(si, sj, C{});
            ans += std::max(0L, std::lower_bound(ss.begin(), ss.end(), sj, C{}) - std::upper_bound(ss.begin(), ss.end(), si, C{}));
        }
    }
    std::cout << ans << std::endl;
    return 0;
}
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