#849822 (C++17) No.1551 誕生日の三角形

• 問題: No.1551 誕生日の三角形
• ユーザー: T101010101
• 提出日時: 2023-03-17 15:39:52
• 言語: C++17 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 2 ms / 1,000 ms
• コード長: 5,693 bytes
• コンパイル時間: 4,056 ms
• コンパイル使用メモリ: 289,568 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-09-18 10:01:33
• 合計ジャッジ時間: 4,783 ms
• ジャッジサーバーID （参考情報）: judge3 / judge2

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	2 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

ソースコード

#pragma region Macros

#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <bits/extc++.h>
using namespace std;
using namespace __gnu_pbds;
// using namespace __gnu_cxx;

// #include <boost/multiprecision/cpp_int.hpp>
// namespace mp = boost::multiprecision;
// using Bint = mp::cpp_int;

#define TO_STRING(var) # var
#define pb emplace_back
#define ture true
#define int ll
#define endl '\n'

using ll = long long;
using ld = long double;
const ld PI = acos(-1);
const ld EPS = 1e-10;
const int INF = 1 << 30;
const ll INFL = 1LL << 61;
// const int MOD = 998244353;
const int MOD = 1000000007;

__attribute__((constructor))
void constructor() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    cout << fixed << setprecision(15);
}

class UnionFind {
public:

	UnionFind() = default;

    UnionFind(int n) : par(n), 
	    sz(n, 1) { iota(par.begin(), par.end(), 0); }

	int root(int x) {
		if (par[x] == x) return x;
		return (par[x] = root(par[x]));
	}

	bool unite(int x, int y) {
		int rx = root(x);
		int ry = root(y);

        if (rx == ry) return false;
		if (sz[rx] < sz[ry]) swap(rx, ry);

		sz[rx] += sz[ry];
		par[ry] = rx;

        return true;
	}

	bool issame(int x, int y) {
		return (root(x) == root(y));
	}

	int size(int x) {
		return sz[root(x)];
	}

    int get_sum(int x) {
        return sum[root(x)];
    }

    vector<vector<int>> groups(int n) {
        vector<vector<int>> G(n);
        for (int x = 0; x < n; x++) {
            G[root(x)].push_back(x);
        }
		G.erase(
            remove_if(G.begin(), G.end(),
                [&](const vector<int>& v) { return v.empty(); }),
                    G.end());
        return G;
    }

private:
	vector<int> par;
	vector<int> sz;
    vector<int> sum;
};

template<int mod> class modint{
public:
    int val = 0;
    modint(int x = 0) { while (x < 0) x += mod; val = x % mod; }
    modint(const modint &r) { val = r.val; }

    modint operator -() { return modint(-val); }
    modint operator +(const modint &r) { return modint(*this) += r; }
    modint operator +(const int &q) { modint r(q); return modint(*this) += r; }
    modint operator -(const modint &r) { return modint(*this) -= r; }
    modint operator -(const int &q) { modint r(q); return modint(*this) -= r; }
    modint operator *(const modint &r) { return modint(*this) *= r; }
    modint operator *(const int &q) { modint r(q); return modint(*this) *= r; }
    modint operator /(const modint &r) { return modint(*this) /= r; }
    modint operator /(const int &q) { modint r(q); return modint(*this) /= r; }
    modint& operator ++() { val = (val + 1) % mod; return *this; }
    modint& operator --() { val = (val - 1 + mod) % mod; return *this; }

    modint &operator +=(const modint &r) {
        val += r.val; if (val >= mod) val -= mod;
        return *this;
    }
    modint &operator +=(const int &q) {
        modint r(q); val += r.val; if (val >= mod) val -= mod;
        return *this;
    }
    modint &operator -=(const modint &r) {
        if (val < r.val) val += mod; val -= r.val;
        return *this;
    }
    modint &operator -=(const int &q) {
        modint r(q);  if (val < r.val) val += mod; val -= r.val;
        return *this;
    }
    modint &operator *=(const modint &r) {
        val = val * r.val % mod;
        return *this;
    }
    modint &operator *=(const int &q) {
        modint r(q); val = val * r.val % mod;
        return *this;
    }
    modint &operator /=(const modint &r) {
        int a = r.val, b = mod, u = 1, v = 0;
        while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);}
        val = val * u % mod; if (val < 0) val += mod;
        return *this;
    }
    modint &operator /=(const int &q) {
        modint r(q); int a = r.val, b = mod, u = 1, v = 0;
        while (b) {int t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v);}
        val = val * u % mod; if (val < 0) val += mod;
        return *this;
    }

    bool operator ==(const modint& r) { return this -> val == r.val; }
    bool operator <(const modint& r) { return this -> val < r.val; }
    bool operator !=(const modint& r) { return this -> val != r.val; }
};

using mint = modint<MOD>;

istream &operator >>(istream &is, mint& x) {
    int t; is >> t;
    x = t;
    return (is);
}
ostream &operator <<(ostream &os, const mint& x) {
    return os << x.val;
}

mint modpow(const mint &a, int n) {
    if (n == 0) return 1;
    mint t = modpow(a, n / 2);
    t = t * t;
    if (n & 1) t = t * a;
    return t;
}

int modpow(int x, int n, int mod) {
    int ret = 1;
    while (n > 0) {
        if (n % 2 == 1) ret = ret * x % mod;
        x = x * x % mod;
        n /= 2;
    }
    return ret;
}

int POW(int x, int y) {
    if (y < 0 or x != 0 && x != 1 && y > 64) {cout << "Error" << endl;return 0;}
    if (y == 0) return 1;
    if (y % 2 == 0) return POW(x * x, y / 2);
    return x * POW(x, y - 1);
}
int ceil(int x, int y) { return (x > 0 ? (x + y - 1) / y : x / y); }

vector<mint> fac, finv, Inv;
void COMinit(int N) {
    fac.resize(N + 1);
    finv.resize(N + 1);
    Inv.resize(N + 1);
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    Inv[1] = 1;
    for (int i = 2; i <= N; i++) {
        fac[i] = fac[i-1] * mint(i);
        Inv[i] = -Inv[MOD % i] * mint(MOD / i);
        finv[i] = finv[i - 1] * Inv[i];
    }
}

mint COM(int N,int K){
    if(N < K)return 0;
    if(N < 0 || K < 0) return 0;
    return fac[N] * finv[K] * finv[N - K];
}

#pragma endregion

signed main() {
    ld L;
    cin >> L;

    L /= 3.;
    cout << L * L * sqrt(3) / 4. << endl;
}