#line 1 "verify/verify-aoj-cgl/aoj-cgl-4-b.test.cpp"
#define PROBLEM "https://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=CGL_4_B"
#define ERROR 0.000001
//
#line 2 "template/template.hpp"
using namespace std;
// intrinstic
#include <immintrin.h>
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <cctype>
#include <cfenv>
#include <cfloat>
#include <chrono>
#include <cinttypes>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdarg>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <deque>
#include <fstream>
#include <functional>
#include <initializer_list>
#include <iomanip>
#include <ios>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <streambuf>
#include <string>
#include <tuple>
#include <type_traits>
#include <typeinfo>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
// utility
#line 3 "template/util.hpp"
namespace Nyaan {
using ll = long long;
using i64 = long long;
using u64 = unsigned long long;
using i128 = __int128_t;
using u128 = __uint128_t;
template <typename T>
using V = vector<T>;
template <typename T>
using VV = vector<vector<T>>;
using vi = vector<int>;
using vl = vector<long long>;
using vd = V<double>;
using vs = V<string>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<long long>>;
template <typename T>
using minpq = priority_queue<T, vector<T>, greater<T>>;
template <typename T, typename U>
struct P : pair<T, U> {
template <typename... Args>
P(Args... args) : pair<T, U>(args...) {}
using pair<T, U>::first;
using pair<T, U>::second;
P &operator+=(const P &r) {
first += r.first;
second += r.second;
return *this;
}
P &operator-=(const P &r) {
first -= r.first;
second -= r.second;
return *this;
}
P &operator*=(const P &r) {
first *= r.first;
second *= r.second;
return *this;
}
template <typename S>
P &operator*=(const S &r) {
first *= r, second *= r;
return *this;
}
P operator+(const P &r) const { return P(*this) += r; }
P operator-(const P &r) const { return P(*this) -= r; }
P operator*(const P &r) const { return P(*this) *= r; }
template <typename S>
P operator*(const S &r) const {
return P(*this) *= r;
}
P operator-() const { return P{-first, -second}; }
};
using pl = P<ll, ll>;
using pi = P<int, int>;
using vp = V<pl>;
constexpr int inf = 1001001001;
constexpr long long infLL = 4004004004004004004LL;
template <typename T>
int sz(const T &t) {
return t.size();
}
template <typename T, typename U>
inline bool amin(T &x, U y) {
return (y < x) ? (x = y, true) : false;
}
template <typename T, typename U>
inline bool amax(T &x, U y) {
return (x < y) ? (x = y, true) : false;
}
template <typename T>
inline T Max(const vector<T> &v) {
return *max_element(begin(v), end(v));
}
template <typename T>
inline T Min(const vector<T> &v) {
return *min_element(begin(v), end(v));
}
template <typename T>
inline long long Sum(const vector<T> &v) {
return accumulate(begin(v), end(v), 0LL);
}
template <typename T>
int lb(const vector<T> &v, const T &a) {
return lower_bound(begin(v), end(v), a) - begin(v);
}
template <typename T>
int ub(const vector<T> &v, const T &a) {
return upper_bound(begin(v), end(v), a) - begin(v);
}
constexpr long long TEN(int n) {
long long ret = 1, x = 10;
for (; n; x *= x, n >>= 1) ret *= (n & 1 ? x : 1);
return ret;
}
template <typename T, typename U>
pair<T, U> mkp(const T &t, const U &u) {
return make_pair(t, u);
}
template <typename T>
vector<T> mkrui(const vector<T> &v, bool rev = false) {
vector<T> ret(v.size() + 1);
if (rev) {
for (int i = int(v.size()) - 1; i >= 0; i--) ret[i] = v[i] + ret[i + 1];
} else {
for (int i = 0; i < int(v.size()); i++) ret[i + 1] = ret[i] + v[i];
}
return ret;
};
template <typename T>
vector<T> mkuni(const vector<T> &v) {
vector<T> ret(v);
sort(ret.begin(), ret.end());
ret.erase(unique(ret.begin(), ret.end()), ret.end());
return ret;
}
template <typename F>
vector<int> mkord(int N, F f) {
vector<int> ord(N);
iota(begin(ord), end(ord), 0);
sort(begin(ord), end(ord), f);
return ord;
}
template <typename T>
vector<int> mkinv(vector<T> &v) {
int max_val = *max_element(begin(v), end(v));
vector<int> inv(max_val + 1, -1);
for (int i = 0; i < (int)v.size(); i++) inv[v[i]] = i;
return inv;
}
vector<int> mkiota(int n) {
vector<int> ret(n);
iota(begin(ret), end(ret), 0);
return ret;
}
template <typename T>
T mkrev(const T &v) {
T w{v};
reverse(begin(w), end(w));
return w;
}
template <typename T>
bool nxp(T &v) {
return next_permutation(begin(v), end(v));
}
// 返り値の型は入力の T に依存
// i 要素目 : [0, a[i])
template <typename T>
vector<vector<T>> product(const vector<T> &a) {
vector<vector<T>> ret;
vector<T> v;
auto dfs = [&](auto rc, int i) -> void {
if (i == (int)a.size()) {
ret.push_back(v);
return;
}
for (int j = 0; j < a[i]; j++) v.push_back(j), rc(rc, i + 1), v.pop_back();
};
dfs(dfs, 0);
return ret;
}
// F : void(T&), mod を取る操作
// T : 整数型のときはオーバーフローに注意する
template <typename T, typename F>
T Power(T a, long long n, const T &I, F &&f) {
static_assert(std::is_invocable_r_v<void, F &, T &>,
"Power callback must be callable as void(T&)");
T res = I;
for (; n; std::invoke(f, a = a * a), n >>= 1) {
if (n & 1) std::invoke(f, res = res * a);
}
return res;
}
// T : 整数型のときはオーバーフローに注意する
template <typename T>
T Power(T a, long long n, const T &I = T{1}) {
auto no_op = [](T &) -> void {};
return Power(a, n, I, no_op);
}
template <typename T>
T Rev(const T &v) {
T res = v;
reverse(begin(res), end(res));
return res;
}
template <typename T>
vector<T> Transpose(const vector<T> &v) {
using U = typename T::value_type;
if(v.empty()) return {};
int H = v.size(), W = v[0].size();
vector res(W, T(H, U{}));
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
res[j][i] = v[i][j];
}
}
return res;
}
template <typename T>
vector<T> Rotate(const vector<T> &v, int clockwise = true) {
using U = typename T::value_type;
int H = v.size(), W = v[0].size();
vector res(W, T(H, U{}));
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
if (clockwise) {
res[W - 1 - j][i] = v[i][j];
} else {
res[j][H - 1 - i] = v[i][j];
}
}
}
return res;
}
} // namespace Nyaan
#line 58 "template/template.hpp"
// bit operation
#line 1 "template/bitop.hpp"
namespace Nyaan {
__attribute__((target("popcnt"))) inline int popcnt(const u64 &a) {
return __builtin_popcountll(a);
}
inline int lsb(const u64 &a) { return a ? __builtin_ctzll(a) : 64; }
inline int ctz(const u64 &a) { return a ? __builtin_ctzll(a) : 64; }
inline int msb(const u64 &a) { return a ? 63 - __builtin_clzll(a) : -1; }
template <typename T>
inline int gbit(const T &a, int i) {
return (a >> i) & 1;
}
template <typename T>
inline void sbit(T &a, int i, bool b) {
if (gbit(a, i) != b) a ^= T(1) << i;
}
constexpr long long PW(int n) { return 1LL << n; }
constexpr long long MSK(int n) { return (1LL << n) - 1; }
} // namespace Nyaan
#line 61 "template/template.hpp"
// inout
#line 1 "template/inout.hpp"
namespace Nyaan {
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
os << p.first << " " << p.second;
return os;
}
template <typename T, typename U>
istream &operator>>(istream &is, pair<T, U> &p) {
is >> p.first >> p.second;
return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
int s = (int)v.size();
for (int i = 0; i < s; i++) os << (i ? " " : "") << v[i];
return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v) {
for (auto &x : v) is >> x;
return is;
}
istream &operator>>(istream &is, __int128_t &x) {
string S;
is >> S;
x = 0;
int flag = 0;
for (auto &c : S) {
if (c == '-') {
flag = true;
continue;
}
x *= 10;
x += c - '0';
}
if (flag) x = -x;
return is;
}
istream &operator>>(istream &is, __uint128_t &x) {
string S;
is >> S;
x = 0;
for (auto &c : S) {
x *= 10;
x += c - '0';
}
return is;
}
ostream &operator<<(ostream &os, __int128_t x) {
if (x == 0) return os << 0;
if (x < 0) os << '-', x = -x;
string S;
while (x) S.push_back('0' + x % 10), x /= 10;
reverse(begin(S), end(S));
return os << S;
}
ostream &operator<<(ostream &os, __uint128_t x) {
if (x == 0) return os << 0;
string S;
while (x) S.push_back('0' + x % 10), x /= 10;
reverse(begin(S), end(S));
return os << S;
}
void in() {}
template <typename T, class... U>
void in(T &t, U &...u) {
cin >> t;
in(u...);
}
void out() { cout << "\n"; }
template <typename T, class... U, char sep = ' '>
void out(const T &t, const U &...u) {
cout << t;
if (sizeof...(u)) cout << sep;
out(u...);
}
struct IoSetupNya {
IoSetupNya() {
cin.tie(nullptr);
ios::sync_with_stdio(false);
cout << fixed << setprecision(15);
cerr << fixed << setprecision(7);
}
} iosetupnya;
} // namespace Nyaan
#line 64 "template/template.hpp"
// debug
#line 1 "template/debug.hpp"
namespace DebugImpl {
template <typename U, typename = void>
struct is_specialize : false_type {};
template <typename U>
struct is_specialize<
U, typename conditional<false, typename U::iterator, void>::type>
: true_type {};
template <typename U>
struct is_specialize<
U, typename conditional<false, decltype(U::first), void>::type>
: true_type {};
template <typename U>
struct is_specialize<U, enable_if_t<is_integral<U>::value, void>> : true_type {
};
void dump(const char& t) { cerr << t; }
void dump(const string& t) { cerr << t; }
void dump(const bool& t) { cerr << (t ? "true" : "false"); }
void dump(__int128_t t) {
if (t == 0) cerr << 0;
if (t < 0) cerr << '-', t = -t;
string S;
while (t) S.push_back('0' + t % 10), t /= 10;
reverse(begin(S), end(S));
cerr << S;
}
void dump(__uint128_t t) {
if (t == 0) cerr << 0;
string S;
while (t) S.push_back('0' + t % 10), t /= 10;
reverse(begin(S), end(S));
cerr << S;
}
template <typename U,
enable_if_t<!is_specialize<U>::value, nullptr_t> = nullptr>
void dump(const U& t) {
cerr << t;
}
template <typename T>
void dump(const T& t, enable_if_t<is_integral<T>::value>* = nullptr) {
string res;
if (t == Nyaan::inf) res = "inf";
if constexpr (is_signed<T>::value) {
if (t == -Nyaan::inf) res = "-inf";
}
if constexpr (sizeof(T) == 8) {
if (t == Nyaan::infLL) res = "inf";
if constexpr (is_signed<T>::value) {
if (t == -Nyaan::infLL) res = "-inf";
}
}
if (res.empty()) res = to_string(t);
cerr << res;
}
template <typename T, typename U>
void dump(const pair<T, U>&);
template <typename T>
void dump(const pair<T*, int>&);
template <typename T>
void dump(const T& t,
enable_if_t<!is_void<typename T::iterator>::value>* = nullptr) {
cerr << "[ ";
for (auto it = t.begin(); it != t.end();) {
dump(*it);
cerr << (++it == t.end() ? "" : ", ");
}
cerr << " ]";
}
template <typename T, typename U>
void dump(const pair<T, U>& t) {
cerr << "( ";
dump(t.first);
cerr << ", ";
dump(t.second);
cerr << " )";
}
template <typename T>
void dump(const pair<T*, int>& t) {
cerr << "[ ";
for (int i = 0; i < t.second; i++) {
dump(t.first[i]);
cerr << (i == t.second - 1 ? "" : ", ");
}
cerr << " ]";
}
void trace() { cerr << endl; }
template <typename Head, typename... Tail>
void trace(Head&& head, Tail&&... tail) {
cerr << " ";
dump(head);
if (sizeof...(tail) != 0) cerr << ",";
trace(std::forward<Tail>(tail)...);
}
} // namespace DebugImpl
#ifdef NyaanDebug
#define trc(...) \
do { \
cerr << "## " << #__VA_ARGS__ << " = "; \
DebugImpl::trace(__VA_ARGS__); \
} while (0)
#else
#define trc(...) (void(0))
#endif
#ifdef NyaanLocal
#define trc2(...) \
do { \
cerr << "## " << #__VA_ARGS__ << " = "; \
DebugImpl::trace(__VA_ARGS__); \
} while (0)
#else
#define trc2(...) (void(0))
#endif
#line 67 "template/template.hpp"
// macro
#line 1 "template/macro.hpp"
#define each(x, v) for (auto&& x : v)
#define each2(x, y, v) for (auto&& [x, y] : v)
#define all(v) (v).begin(), (v).end()
#define rep(i, N) for (long long i = 0; i < (long long)(N); i++)
#define repr(i, N) for (long long i = (long long)(N)-1; i >= 0; i--)
#define rep1(i, N) for (long long i = 1; i <= (long long)(N); i++)
#define repr1(i, N) for (long long i = (N); (long long)(i) > 0; i--)
#define reg(i, a, b) for (long long i = (a); i < (b); i++)
#define regr(i, a, b) for (long long i = (b)-1; i >= (a); i--)
#define fi first
#define se second
#define ini(...) \
int __VA_ARGS__; \
in(__VA_ARGS__)
#define inl(...) \
long long __VA_ARGS__; \
in(__VA_ARGS__)
#define ins(...) \
string __VA_ARGS__; \
in(__VA_ARGS__)
#define in2(s, t) \
for (int i = 0; i < (int)s.size(); i++) { \
in(s[i], t[i]); \
}
#define in3(s, t, u) \
for (int i = 0; i < (int)s.size(); i++) { \
in(s[i], t[i], u[i]); \
}
#define in4(s, t, u, v) \
for (int i = 0; i < (int)s.size(); i++) { \
in(s[i], t[i], u[i], v[i]); \
}
#define die(...) \
do { \
Nyaan::out(__VA_ARGS__); \
return; \
} while (0)
#line 70 "template/template.hpp"
namespace Nyaan {
void solve();
}
int main() { Nyaan::solve(); }
#line 5 "verify/verify-aoj-cgl/aoj-cgl-4-b.test.cpp"
//
#line 2 "geometry/polygon.hpp"
#line 2 "geometry/geometry-base.hpp"
#line 9 "geometry/geometry-base.hpp"
using namespace std;
using Real = long double;
constexpr Real EPS = 1e-10;
constexpr Real pi = 3.141592653589793238462643383279L;
bool equals(Real a, Real b) { return fabs(b - a) < EPS; }
int sign(Real a) { return equals(a, 0) ? 0 : a > 0 ? 1 : -1; }
template <typename R>
struct PointBase {
using P = PointBase;
R x, y;
PointBase() : x(0), y(0) {}
PointBase(R _x, R _y) : x(_x), y(_y) {}
template <typename T, typename U>
PointBase(const pair<T, U>& p) : x(p.first), y(p.second) {}
P operator+(const P& r) const { return {x + r.x, y + r.y}; }
P operator-(const P& r) const { return {x - r.x, y - r.y}; }
P operator*(R r) const { return {x * r, y * r}; }
P operator/(R r) const { return {x / r, y / r}; }
P& operator+=(const P& r) { return (*this) = (*this) + r; }
P& operator-=(const P& r) { return (*this) = (*this) - r; }
P& operator*=(R r) { return (*this) = (*this) * r; }
P& operator/=(R r) { return (*this) = (*this) / r; }
bool operator<(const P& r) const { return x != r.x ? x < r.x : y < r.y; }
bool operator==(const P& r) const { return x == r.x and y == r.y; }
bool operator!=(const P& r) const { return !((*this) == r); }
P rotate(R rad) const {
return {x * cos(rad) - y * sin(rad), x * sin(rad) + y * cos(rad)};
}
R real() const { return x; }
R imag() const { return y; }
friend R real(const P& p) { return p.x; }
friend R imag(const P& p) { return p.y; }
friend R dot(const P& l, const P& r) { return l.x * r.x + l.y * r.y; }
friend R cross(const P& l, const P& r) { return l.x * r.y - l.y * r.x; }
friend R abs(const P& p) { return sqrt(p.x * p.x + p.y * p.y); }
friend R norm(const P& p) { return p.x * p.x + p.y * p.y; }
friend R arg(const P& p) { return atan2(p.y, p.x); }
friend istream& operator>>(istream& is, P& p) {
R a, b;
is >> a >> b;
p = P{a, b};
return is;
}
friend ostream& operator<<(ostream& os, const P& p) {
return os << p.x << " " << p.y;
}
};
using Point = PointBase<Real>;
using Points = vector<Point>;
// ccw, 点の進行方向
int ccw(const Point& a, const Point& b, const Point& c) {
Point x = b - a, y = c - a;
if (cross(x, y) > EPS) return +1; // 反時計回り
if (cross(x, y) < -EPS) return -1; // 時計回り
if (min(norm(x), norm(y)) < EPS * EPS) return 0; // c=a または c=b
if (dot(x, y) < EPS) return +2; // c-a-b の順で一直線
if (norm(x) < norm(y)) return -2; // a-b-c の順で一直線
return 0; // a-c-b の順で一直線
}
#line 4 "geometry/polygon.hpp"
using Polygon = vector<Point>;
// 多角形の内部に点があるか？
// OUT : 0, ON : 1, IN : 2
int contains_polygon(const Polygon &Q, const Point &p) {
bool in = false;
for (int i = 0; i < (int)Q.size(); i++) {
Point a = Q[i] - p, b = Q[(i + 1) % Q.size()] - p;
if (imag(a) > imag(b)) swap(a, b);
if (sign(imag(a)) <= 0 && 0 < sign(imag(b)) && sign(cross(a, b)) < 0)
in = !in;
if (equals(cross(a, b), 0) && sign(dot(a, b)) <= 0) return 1;
}
return in ? 2 : 0;
}
// 多角形の面積
Real area(const Polygon &p) {
Real A = 0;
for (int i = 0; i < (int)p.size(); ++i) {
A += cross(p[i], p[(i + 1) % p.size()]);
}
return A * 0.5;
}
// 頂点集合から凸包を生成
// boundary : 周上の点も列挙する場合 true
template <bool boundary = false>
Polygon convex_hull(vector<Point> ps) {
sort(begin(ps), end(ps));
ps.erase(unique(begin(ps), end(ps)), end(ps));
int n = ps.size(), k = 0;
if (n <= 2) return ps;
vector<Point> ch(2 * n);
// 反時計周り
Real th = boundary ? -EPS : +EPS;
for (int i = 0; i < n; ch[k++] = ps[i++]) {
while (k >= 2 && cross(ch[k - 1] - ch[k - 2], ps[i] - ch[k - 1]) < th) --k;
}
for (int i = n - 2, t = k + 1; i >= 0; ch[k++] = ps[i--]) {
while (k >= t && cross(ch[k - 1] - ch[k - 2], ps[i] - ch[k - 1]) < th) --k;
}
ch.resize(k - 1);
return ch;
}
// 凸包の内部に点があるか？
// OUT : 0, ON : 1, IN : 2
int contains_convex(const Polygon &C, const Point &p) {
int N = C.size();
auto b1 = cross(C[1] - C[0], p - C[0]);
auto b2 = cross(C[N - 1] - C[0], p - C[0]);
if (b1 < -EPS or b2 > EPS) return 0;
int L = 1, R = N - 1;
while (L + 1 < R) {
int M = (L + R) / 2;
(cross(p - C[0], C[M] - C[0]) >= 0 ? R : L) = M;
}
auto v = cross(C[L] - p, C[R] - p);
if (equals(v, 0)) {
return 1;
} else if (v > 0) {
return equals(b1, 0) or equals(b2, 0) ? 1 : 2;
} else {
return 0;
}
}
// 凸包が与えられるので最遠点対を返す
// 返り値：頂点番号のペア
pair<int, int> convex_polygon_diameter(const Polygon &p) {
int N = (int)p.size();
int is = 0, js = 0;
for (int i = 1; i < N; i++) {
if (imag(p[i]) > imag(p[is])) is = i;
if (imag(p[i]) < imag(p[js])) js = i;
}
Real maxdis = norm(p[is] - p[js]);
int maxi, maxj, i, j;
i = maxi = is;
j = maxj = js;
do {
if (cross(p[(i + 1) % N] - p[i], p[(j + 1) % N] - p[j]) >= 0) {
j = (j + 1) % N;
} else {
i = (i + 1) % N;
}
if (norm(p[i] - p[j]) > maxdis) {
maxdis = norm(p[i] - p[j]);
maxi = i;
maxj = j;
}
} while (i != is || j != js);
return minmax(maxi, maxj);
}
#line 7 "verify/verify-aoj-cgl/aoj-cgl-4-b.test.cpp"
using namespace Nyaan;
void q() {
ini(N);
Polygon p(N);
in(p);
auto [i, j] = convex_polygon_diameter(p);
out(abs(p[i] - p[j]));
}
void Nyaan::solve() {
int t = 1;
// in(t);
while (t--) q();
}
verify/verify-aoj-cgl/aoj-cgl-4-b.test.cpp