#779098 (C++17) No.2012 Largest Triangle

提出ソース

結果

問題	No.2012 Largest Triangle
ユーザー	srtubaki
提出日時	2022-07-16 02:19:53
言語	C++17 (gcc 12.3.0 + boost 1.83.0)
結果	AC
実行時間	106 ms / 2,500 ms
コード長	7,709 bytes
コンパイル時間	2,231 ms
コンパイル使用メモリ	213,588 KB
実行使用メモリ	22,536 KB
最終ジャッジ日時	2024-06-28 00:32:15
合計ジャッジ時間	6,214 ms
ジャッジサーバーID （参考情報）	judge4 / judge2

このコードへのチャレンジ
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テストケース

テストケース表示

入力	結果	実行時間実行使用メモリ
testcase_00	AC	2 ms 5,248 KB
testcase_01	AC	2 ms 5,376 KB
testcase_02	AC	2 ms 5,376 KB
testcase_03	AC	2 ms 5,376 KB
testcase_04	AC	2 ms 5,376 KB
testcase_05	AC	2 ms 5,376 KB
testcase_06	AC	2 ms 5,376 KB
testcase_07	AC	1 ms 5,376 KB
testcase_08	AC	2 ms 5,376 KB
testcase_09	AC	2 ms 5,376 KB
testcase_10	AC	2 ms 5,376 KB
testcase_11	AC	2 ms 5,376 KB
testcase_12	AC	2 ms 5,376 KB
testcase_13	AC	2 ms 5,376 KB
testcase_14	AC	2 ms 5,376 KB
testcase_15	AC	1 ms 5,376 KB
testcase_16	AC	104 ms 21,884 KB
testcase_17	AC	105 ms 22,012 KB
testcase_18	AC	103 ms 22,016 KB
testcase_19	AC	105 ms 21,832 KB
testcase_20	AC	104 ms 22,024 KB
testcase_21	AC	105 ms 22,028 KB
testcase_22	AC	104 ms 21,896 KB
testcase_23	AC	106 ms 21,840 KB
testcase_24	AC	103 ms 21,984 KB
testcase_25	AC	105 ms 22,024 KB
testcase_26	AC	106 ms 22,476 KB
testcase_27	AC	106 ms 22,408 KB
testcase_28	AC	105 ms 22,536 KB
testcase_29	AC	106 ms 22,408 KB
testcase_30	AC	106 ms 22,536 KB
testcase_31	AC	106 ms 22,028 KB
testcase_32	AC	104 ms 22,024 KB
testcase_33	AC	105 ms 22,016 KB
testcase_34	AC	106 ms 21,896 KB
testcase_35	AC	105 ms 22,000 KB
testcase_36	AC	2 ms 5,376 KB
testcase_37	AC	3 ms 5,376 KB
testcase_38	AC	2 ms 5,376 KB
testcase_39	AC	3 ms 5,376 KB
testcase_40	AC	3 ms 5,376 KB
testcase_41	AC	32 ms 10,548 KB

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

raw source code

#line 1 "/home/srtubaki/atcoder/a/tpl.cpp"
#pragma region template

#include <bits/stdc++.h>

using namespace std;

// clang-format off
using ll  = long long;    using vl   = vector<ll>;  using vvl   = vector<vl>;
using ld  = long double;  using vld  = vector<ld>;  using vvld  = vector<vld>;
using pll = pair<ll, ll>; using vpll = vector<pll>; using vvpll = vector<vpll>;
using vb = vector<bool>;  using vvb = vector<vector<bool>>;
using vs = vector<string>;
using mll = map<ll, ll>;
template <class T> using max_heap = priority_queue<T>;
template <class T> using min_heap = priority_queue<T, vector<T>, greater<T>>;


constexpr ll inf = 3001001000100100100LL;

#define  _overload(_1, _2, _3, name, ...) name
#define   rep(...) _overload(__VA_ARGS__,   _rep,   _rep2,)(__VA_ARGS__)
#define  repc(...) _overload(__VA_ARGS__,  _repc,  _repc2,)(__VA_ARGS__)
#define  repr(...) _overload(__VA_ARGS__,  _repr,  _repr2,)(__VA_ARGS__)
#define reprc(...) _overload(__VA_ARGS__, _reprc, _reprc2,)(__VA_ARGS__)
#define   _rep(i,k,n) for(ll i=(k)  , i##_xxxx=(n); i < i##_xxxx; ++i)
#define  _repc(i,k,n) for(ll i=(k)  , i##_xxxx=(n); i <=i##_xxxx; ++i)
#define  _repr(i,k,n) for(ll i=(n)-1, i##_xxxx=(k); i >=i##_xxxx; --i)
#define _reprc(i,k,n) for(ll i=(n)  , i##_xxxx=(k); i >=i##_xxxx; --i)
#define   _rep2(i,n)   _rep(i,0,n)
#define  _repc2(i,n)  _repc(i,1,n)
#define  _repr2(i,n)  _repr(i,0,n)
#define _reprc2(i,n) _reprc(i,1,n)

#define all(o) begin(o), end(o)
#define rall(o) rbegin(o), rend(o)
template <class C> ll sz(const C& c) { return static_cast<ll>(c.size()); }
template <class T> bool chmax(T& m, const T& v){ if (v > m){ m = v; return true; } return false; }
template <class T> bool chmin(T& m, const T& v){ if (v < m){ m = v; return true; } return false; }
template <class T> T cdiv(const T& a, const T& b){ return (a + b - 1) / b; }
template <class T> T rdiv(const T& a, const T& b){ return (a + b / 2) / b; }

template <class T, class S>             string join(const T& v, const S& sep                  ){ stringstream ss; bool f = false; for (const auto& e : v){ if (f) ss << sep; f = true; ss << e;} return ss.str(); }
template <class T, class S, class... U> string join(const T& v, const S& sep, const U& ...args){ stringstream ss; bool f = false; for (const auto& c : v){ if (f) ss << sep; f = true; ss << join(c, args...); } return ss.str(); }
template <class T>            ostream& operator<<(ostream& os, const vector<T>&            seq){ os << '[' << join(seq, ",") << ']'; return os; }
template <class T>            ostream& operator<<(ostream& os, const vector<vector<T>>&    seq){ os << '[' << join(seq, ",\n ") << ']'; return os; }
template <class T>            ostream& operator<<(ostream& os, const deque<T>&             seq){ os << '[' << join(seq, ",") << ']'; return os; }
template <class T>            ostream& operator<<(ostream& os, const set<T>&               seq){ os << '{' << join(seq, ",") << '}'; return os; }
template <class T , class TH> ostream& operator<<(ostream& os, const unordered_set<T, TH>& seq){ os << '{' << join(seq, ",") << '}'; return os; }
template <class TK, class TV> ostream& operator<<(ostream& os, const map<TK, TV>&          seq){ os << '{'; bool f = false; for (const auto& e : seq){ if (f) os << ','; f = true; os << e.first << ":" << e.second; } os << '}'; return os; }
template <class T1, class T2> ostream& operator<<(ostream& os, const pair<T1, T2>&          pa){ os << '(' << pa.first << ',' << pa.second << ')'; return os; }

#if LOCAL
#define debug(...) _debug(__VA_ARGS__, __LINE__)
#else
#define debug(...)
#endif
void print() { std::cout << '\n'; }
template <class S>             void  print(const S& a){ std::cout << a << '\n'; }
template <class S>             void _debug(const S& a){ std::cerr << "(L:" << std::setw(3) << a << ")\n"; }
template <class S, class... T> void  print(const S& a, const T&... args){ std::cout << a << ' ';  print(args...); }
template <class S, class... T> void _debug(const S& a, const T&... args){ std::cerr << a << ' '; _debug(args...); }
#define endl '\n'
struct setup_main { setup_main() { std::cin.tie(nullptr); std::ios::sync_with_stdio(false); std::cout << fixed << setprecision(15); } } setup_main_;
// clang-format on
#pragma endregion


template <class T>
struct Point {
    T x, y;
    bool operator<(const Point& b) const { return x < b.x or (x == b.x and y < b.y); }
    Point operator-() const { return Point{-x, -y}; }
    Point operator+() const { return *this; }

    Point& operator+=(const Point& b) { x += b.x, y += b.y; return *this; }
    Point& operator-=(const Point& b) { x -= b.x, y -= b.y; return *this; }
    Point& operator*=(const T& c)     { x *= c,   y *= c;   return *this; }
    Point& operator/=(const T& c)     { x /= c,   y /= c;   return *this; }

    friend Point operator+(const Point& a, const Point& b) { return Point(a) += b; }
    friend Point operator-(const Point& a, const Point& b) { return Point(a) -= b; }
    friend Point operator*(const Point& a, const T& c)     { return Point(a) *= c; }
    friend Point operator*(const T& c,     const Point& a) { return Point(a) *= c; }
    friend Point operator/(const Point& a, const T& c)     { return Point(a) /= c; }
    friend Point operator/(const T& c,     const Point& a) { return Point(a) /= c; }

    friend bool operator==(const Point& a, const Point& b) { return a.x == b.x && a.y == b.y; }
    friend bool operator!=(const Point& a, const Point& b) { return !(a == b); }

    T cross(const Point& b) const { return (x * b.y - b.x * y); }
    friend T cross(const Point& a, const Point& b) { return a.cross(b); }
    friend ostream& operator<<(ostream& os, const Point& p) {
        os << make_pair(p.x, p.y);
        return os;
    }
};


// 凸包
template <class T>
vector<Point<T>> convex_calc(vector<Point<T>>& P) {
    vector<Point<ll>> S;
    for (auto&& p1 : P) {
        while (sz(S) >= 2) {
            Point<T> p2 = S.back();
            S.pop_back();
            Point<T> p3 = S.back();
            if (cross(p2 - p1, p3 - p2) < 0) {
                S.push_back(p2);
                break;
            }
        }
        S.push_back(p1);
    }
    return S;
}

template <class T>
vector<Point<T>> convex_hull_upper(vector<Point<T>> P) {
    sort(all(P));
    return convex_calc(P);
}

template <class T>
vector<Point<T>> convex_hull_lower(vector<Point<T>> P) {
    sort(rall(P));
    return convex_calc(P);
}

template <class T>
vector<Point<T>> convex_hull(vector<Point<T>> P) {
    sort(all(P));
    vector<Point<T>> u = convex_calc(P);
    reverse(all(P));
    vector<Point<T>> l = convex_calc(P);
    rep(i, 1, l.size() - 1) u.push_back(l[i]);
    return u;
}
#line 2 "main.cpp"


/*/
凸包上の点だけ考えれば良い
底辺を決め打って、高さを3分探索
    倍加すると探索が楽
/*/

void solve(ll N, vector<ll> X, vector<ll> Y) {
    vector<Point<ll>> P(N);

    rep(i, N) P[i] = {X[i], Y[i]};
    rep(i, N) P.push_back(-P[i]);

    P = convex_hull(P);


    ll ans = 0;

    N = sz(P) / 2;

    rep(i, N) {
        Point<ll> p = P[i];
        auto f = [&](Point<ll> pl, Point<ll> pr) { return abs(cross(p, pl)) < abs(cross(p, pr)); };

        ll l = i, r = i + N;
        while (r - l > 2) {
            ll ml = l + (r - l) / 3, mr = r - (r - l) / 3;
            if (f(P[ml], P[mr]))
                l = ml;
            else
                r = mr;
        }

        chmax(ans, abs(cross(p, P[l])));
        chmax(ans, abs(cross(p, P[(r + l) / 2])));
        chmax(ans, abs(cross(p, P[r])));
    }

    print(ans);
}


int main() {
    int N;
    cin >> N;
    vector<ll> x(N), y(N);
    rep(i, N) {
        cin >> x[i] >> y[i];
    }

    solve(N, x, y);
}

yukicoder

結果

テストケース

ソースコード