#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using lint = long long; using pint = pair; using plint = pair; struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_; #define ALL(x) (x).begin(), (x).end() #define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i=i##_begin_;i--) #define REP(i, n) FOR(i,0,n) #define IREP(i, n) IFOR(i,0,n) template void ndarray(vector& vec, const V& val, int len) { vec.assign(len, val); } template void ndarray(vector& vec, const V& val, int len, Args... args) { vec.resize(len), for_each(begin(vec), end(vec), [&](T& v) { ndarray(v, val, args...); }); } template bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; } template bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; } const std::vector> grid_dxs{{1, 0}, {-1, 0}, {0, 1}, {0, -1}}; int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); } template T1 floor_div(T1 num, T2 den) { return (num > 0 ? num / den : -((-num + den - 1) / den)); } template std::pair operator+(const std::pair &l, const std::pair &r) { return std::make_pair(l.first + r.first, l.second + r.second); } template std::pair operator-(const std::pair &l, const std::pair &r) { return std::make_pair(l.first - r.first, l.second - r.second); } template std::vector sort_unique(std::vector vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; } template int arglb(const std::vector &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); } template int argub(const std::vector &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); } template IStream &operator>>(IStream &is, std::vector &vec) { for (auto &v : vec) is >> v; return is; } template OStream &operator<<(OStream &os, const std::vector &vec); template OStream &operator<<(OStream &os, const std::array &arr); template OStream &operator<<(OStream &os, const std::unordered_set &vec); template OStream &operator<<(OStream &os, const pair &pa); template OStream &operator<<(OStream &os, const std::deque &vec); template OStream &operator<<(OStream &os, const std::set &vec); template OStream &operator<<(OStream &os, const std::multiset &vec); template OStream &operator<<(OStream &os, const std::unordered_multiset &vec); template OStream &operator<<(OStream &os, const std::pair &pa); template OStream &operator<<(OStream &os, const std::map &mp); template OStream &operator<<(OStream &os, const std::unordered_map &mp); template OStream &operator<<(OStream &os, const std::tuple &tpl); template OStream &operator<<(OStream &os, const std::vector &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; } template OStream &operator<<(OStream &os, const std::array &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']'; return os; } template std::istream &operator>>(std::istream &is, std::tuple &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; } template OStream &operator<<(OStream &os, const std::tuple &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; } template OStream &operator<<(OStream &os, const std::unordered_set &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template OStream &operator<<(OStream &os, const std::deque &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; } template OStream &operator<<(OStream &os, const std::set &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template OStream &operator<<(OStream &os, const std::multiset &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template OStream &operator<<(OStream &os, const std::unordered_multiset &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; } template OStream &operator<<(OStream &os, const std::pair &pa) { return os << '(' << pa.first << ',' << pa.second << ')'; } template OStream &operator<<(OStream &os, const std::map &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; } template OStream &operator<<(OStream &os, const std::unordered_map &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; } #ifdef HITONANODE_LOCAL const string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m"; #define dbg(x) std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl #define dbgif(cond, x) ((cond) ? std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl : std::cerr) #else #define dbg(x) ((void)0) #define dbgif(cond, x) ((void)0) #endif // Subset sum (fast zeta transform) // Complexity: O(N 2^N) for array of size 2^N template void subset_sum(std::vector &f) { const int sz = f.size(), n = __builtin_ctz(sz); assert(__builtin_popcount(sz) == 1); for (int d = 0; d < n; d++) { for (int S = 0; S < 1 << n; S++) if (S & (1 << d)) f[S] += f[S ^ (1 << d)]; } } // Inverse of subset sum (fast moebius transform) // Complexity: O(N 2^N) for array of size 2^N template void subset_sum_inv(std::vector &g) { const int sz = g.size(), n = __builtin_ctz(sz); assert(__builtin_popcount(sz) == 1); for (int d = 0; d < n; d++) { for (int S = 0; S < 1 << n; S++) if (S & (1 << d)) g[S] -= g[S ^ (1 << d)]; } } // Superset sum / its inverse (fast zeta/moebius transform) // Complexity: O(N 2^N) for array of size 2^N template void superset_sum(std::vector &f) { const int sz = f.size(), n = __builtin_ctz(sz); assert(__builtin_popcount(sz) == 1); for (int d = 0; d < n; d++) { for (int S = 0; S < 1 << n; S++) if (!(S & (1 << d))) f[S] += f[S | (1 << d)]; } } template void superset_sum_inv(std::vector &g) { const int sz = g.size(), n = __builtin_ctz(sz); assert(__builtin_popcount(sz) == 1); for (int d = 0; d < n; d++) { for (int S = 0; S < 1 << n; S++) if (!(S & (1 << d))) g[S] -= g[S | (1 << d)]; } } template std::vector> build_zeta_(int D, const std::vector &f) { int n = f.size(); std::vector> ret(D, std::vector(n)); for (int i = 0; i < n; i++) ret[__builtin_popcount(i)][i] += f[i]; for (auto &vec : ret) subset_sum(vec); return ret; } template std::vector get_moebius_of_prod_(const std::vector> &mat1, const std::vector> &mat2) { int D = mat1.size(), n = mat1[0].size(); std::vector> pc2i(D); for (int i = 0; i < n; i++) pc2i[__builtin_popcount(i)].push_back(i); std::vector tmp, ret(mat1[0].size()); for (int d = 0; d < D; d++) { tmp.assign(mat1[d].size(), 0); for (int e = 0; e <= d; e++) { for (int i = 0; i < int(tmp.size()); i++) tmp[i] += mat1[e][i] * mat2[d - e][i]; } subset_sum_inv(tmp); for (auto i : pc2i[d]) ret[i] = tmp[i]; } return ret; }; // Subset convolution // h[S] = \sum_T f[T] * g[S - T] // Complexity: O(N^2 2^N) for arrays of size 2^N template std::vector subset_convolution(std::vector f, std::vector g) { const int sz = f.size(), m = __builtin_ctz(sz) + 1; assert(__builtin_popcount(sz) == 1 and f.size() == g.size()); auto ff = build_zeta_(m, f), fg = build_zeta_(m, g); return get_moebius_of_prod_(ff, fg); } // https://hos-lyric.hatenablog.com/entry/2021/01/14/201231 template void subset_func(std::vector &f, const Function &func) { const int sz = f.size(), m = __builtin_ctz(sz) + 1; assert(__builtin_popcount(sz) == 1); auto ff = build_zeta_(m, f); std::vector p(m); for (int i = 0; i < sz; i++) { for (int d = 0; d < m; d++) p[d] = ff[d][i]; func(p); for (int d = 0; d < m; d++) ff[d][i] = p[d]; } for (auto &vec : ff) subset_sum_inv(vec); for (int i = 0; i < sz; i++) f[i] = ff[__builtin_popcount(i)][i]; } // log(f(x)) for f(x), f(0) == 1 // Requires inv() template void poly_log(std::vector &f) { assert(f.at(0) == T(1)); static std::vector invs{0}; const int m = f.size(); std::vector finv(m); for (int d = 0; d < m; d++) { finv[d] = (d == 0); if (int(invs.size()) <= d) invs.push_back(T(d).inv()); for (int e = 0; e < d; e++) finv[d] -= finv[e] * f[d - e]; } std::vector ret(m); for (int d = 1; d < m; d++) { for (int e = 0; d + e < m; e++) ret[d + e] += f[d] * d * finv[e] * invs[d + e]; } f = ret; } // log(f(S)) for set function f(S), f(0) == 1 // Requires inv() // Complexity: O(n^2 2^n) // https://atcoder.jp/contests/abc213/tasks/abc213_g template void subset_log(std::vector &f) { subset_func(f, poly_log); } // exp(f(S)) for set function f(S), f(0) == 0 // Complexity: O(n^2 2^n) // https://codeforces.com/blog/entry/92183 template void subset_exp(std::vector &f) { const int sz = f.size(), m = __builtin_ctz(sz); assert(sz == 1 << m); assert(f.at(0) == 0); std::vector ret{T(1)}; ret.reserve(sz); for (int d = 0; d < m; d++) { auto c = subset_convolution({f.begin() + (1 << d), f.begin() + (1 << (d + 1))}, ret); ret.insert(ret.end(), c.begin(), c.end()); } f = ret; } // sqrt(f(x)), f(x) == 1 // Requires inv of 2 // Compelxity: O(n^2) template void poly_sqrt(std::vector &f) { assert(f.at(0) == T(1)); const int m = f.size(); static const auto inv2 = T(2).inv(); for (int d = 1; d < m; d++) { if (~(d & 1)) f[d] -= f[d / 2] * f[d / 2]; f[d] *= inv2; for (int e = 1; e < d - e; e++) f[d] -= f[e] * f[d - e]; } } // sqrt(f(S)) for set function f(S), f(0) == 1 // Requires inv() // https://atcoder.jp/contests/xmascon20/tasks/xmascon20_h template void subset_sqrt(std::vector &f) { subset_func(f, poly_sqrt); } // exp(f(S)) for set function f(S), f(0) == 0 template void poly_exp(std::vector &P) { const int m = P.size(); assert(m and P[0] == 0); std::vector Q(m), logQ(m), Qinv(m); Q[0] = Qinv[0] = T(1); static std::vector invs{0}; auto set_invlog = [&](int d) { Qinv[d] = 0; for (int e = 0; e < d; e++) Qinv[d] -= Qinv[e] * Q[d - e]; while (d >= int(invs.size())) { int sz = invs.size(); invs.push_back(T(sz).inv()); } logQ[d] = 0; for (int e = 1; e <= d; e++) logQ[d] += Q[e] * e * Qinv[d - e]; logQ[d] *= invs[d]; }; for (int d = 1; d < m; d++) { Q[d] += P[d] - logQ[d]; set_invlog(d); assert(logQ[d] == P[d]); if (d + 1 < m) set_invlog(d + 1); } P = Q; } // f(S)^k for set function f(S) // Requires inv() template void subset_pow(std::vector &f, long long k) { auto poly_pow = [&](std::vector &f) { const int m = f.size(); if (k == 0) f[0] = 1, std::fill(f.begin() + 1, f.end(), T(0)); if (k <= 1) return; int nzero = 0; while (nzero < int(f.size()) and f[nzero] == T(0)) nzero++; int rem = std::max((long long)f.size() - nzero * k, 0LL); if (rem == 0) { std::fill(f.begin(), f.end(), 0); return; } f.erase(f.begin(), f.begin() + nzero); f.resize(rem); const T f0 = f.at(0), f0inv = f0.inv(), f0pow = f0.pow(k); for (auto &x : f) x *= f0inv; poly_log(f); for (auto &x : f) x *= k; poly_exp(f); for (auto &x : f) x *= f0pow; f.resize(rem, 0); f.insert(f.begin(), m - int(f.size()), T(0)); }; subset_func(f, poly_pow); } #include #include #include #include #include #include #include #include template struct Point2d { static T_P EPS; static void set_eps(T_P e) { EPS = e; } T_P x, y; Point2d() : x(0), y(0) {} Point2d(T_P x, T_P y) : x(x), y(y) {} Point2d(const std::pair &p) : x(p.first), y(p.second) {} Point2d(const std::complex &p) : x(p.real()), y(p.imag()) {} std::complex to_complex() const noexcept { return {x, y}; } Point2d operator+(const Point2d &p) const noexcept { return Point2d(x + p.x, y + p.y); } Point2d operator-(const Point2d &p) const noexcept { return Point2d(x - p.x, y - p.y); } Point2d operator*(const Point2d &p) const noexcept { static_assert(std::is_floating_point::value == true); return Point2d(x * p.x - y * p.y, x * p.y + y * p.x); } Point2d operator*(T_P d) const noexcept { return Point2d(x * d, y * d); } Point2d operator/(T_P d) const noexcept { static_assert(std::is_floating_point::value == true); return Point2d(x / d, y / d); } Point2d inv() const { static_assert(std::is_floating_point::value == true); return conj() / norm2(); } Point2d operator/(const Point2d &p) const { return (*this) * p.inv(); } bool operator<(const Point2d &r) const noexcept { return x != r.x ? x < r.x : y < r.y; } bool operator==(const Point2d &r) const noexcept { return x == r.x and y == r.y; } bool operator!=(const Point2d &r) const noexcept { return !((*this) == r); } T_P dot(Point2d p) const noexcept { return x * p.x + y * p.y; } T_P det(Point2d p) const noexcept { return x * p.y - y * p.x; } T_P absdet(Point2d p) const noexcept { return std::abs(det(p)); } T_P norm() const noexcept { static_assert(std::is_floating_point::value == true); return std::sqrt(x * x + y * y); } T_P norm2() const noexcept { return x * x + y * y; } T_P arg() const noexcept { return std::atan2(y, x); } // rotate point/vector by rad Point2d rotate(T_P rad) const noexcept { static_assert(std::is_floating_point::value == true); return Point2d(x * std::cos(rad) - y * std::sin(rad), x * std::sin(rad) + y * std::cos(rad)); } Point2d normalized() const { static_assert(std::is_floating_point::value == true); return (*this) / this->norm(); } Point2d conj() const noexcept { return Point2d(x, -y); } template friend IStream &operator>>(IStream &is, Point2d &p) { T_P x, y; is >> x >> y; p = Point2d(x, y); return is; } template friend OStream &operator<<(OStream &os, const Point2d &p) { return os << '(' << p.x << ',' << p.y << ')'; } }; template <> double Point2d::EPS = 1e-9; template <> long double Point2d::EPS = 1e-12; template <> long long Point2d::EPS = 0; template int ccw(const Point2d &a, const Point2d &b, const Point2d &c) { // a->b->cの曲がり方 Point2d v1 = b - a; Point2d v2 = c - a; if (v1.det(v2) > Point2d::EPS) return 1; // 左折 if (v1.det(v2) < -Point2d::EPS) return -1; // 右折 if (v1.dot(v2) < -Point2d::EPS) return 2; // c-a-b if (v1.norm() < v2.norm()) return -2; // a-b-c return 0; // a-c-b } // Convex hull (凸包) // return: IDs of vertices used for convex hull, counterclockwise // include_boundary: If true, interior angle pi is allowed template std::vector convex_hull(const std::vector> &ps, bool include_boundary = false) { int n = ps.size(); if (n <= 1) return std::vector(n, 0); std::vector, int>> points(n); for (size_t i = 0; i < ps.size(); i++) points[i] = std::make_pair(ps[i], i); std::sort(points.begin(), points.end()); int k = 0; std::vector, int>> qs(2 * n); auto ccw_check = [&](int c) { return include_boundary ? (c == -1) : (c <= 0); }; for (int i = 0; i < n; i++) { while (k > 1 and ccw_check(ccw(qs[k - 2].first, qs[k - 1].first, points[i].first))) k--; qs[k++] = points[i]; } for (int i = n - 2, t = k; i >= 0; i--) { while (k > t and ccw_check(ccw(qs[k - 2].first, qs[k - 1].first, points[i].first))) k--; qs[k++] = points[i]; } std::vector ret(k - 1); for (int i = 0; i < k - 1; i++) ret[i] = qs[i].second; return ret; } #include // Solve r1 + t1 * v1 == r2 + t2 * v2 template ::value>::type * = nullptr> std::optional> lines_crosspoint(Point2d r1, Point2d v1, Point2d r2, Point2d v2) { static_assert(std::is_floating_point::value == true); if (abs(v2.det(v1)) <= Point2d::EPS) return nullopt; return r1 + v1 * (v2.det(r2 - r1) / v2.det(v1)); } // Whether two segments s1t1 & s2t2 intersect or not (endpoints not included) // Google Code Jam 2013 Round 3 - Rural Planning // Google Code Jam 2021 Round 3 - Fence Design template bool intersect_open_segments(Point2d s1, Point2d t1, Point2d s2, Point2d t2) { if (s1 == t1 or s2 == t2) return false; // Not segment but point int nbad = 0; for (int t = 0; t < 2; t++) { Point2d v1 = t1 - s1, v2 = t2 - s2; T den = v2.det(v1); if (den == 0) { if (s1.det(v1) == s2.det(v1)) { auto L1 = s1.dot(v1), R1 = t1.dot(v1); auto L2 = s2.dot(v1), R2 = t2.dot(v1); if (L1 > R1) std::swap(L1, R1); if (L2 > R2) std::swap(L2, R2); if (L1 > L2) std::swap(L1, L2), std::swap(R1, R2); return R1 > L2; } else { return false; } } else { auto num = v2.det(s2 - s1); if ((0 < num and num < den) or (den < num and num < 0)) nbad++; } std::swap(s1, s2); std::swap(t1, t2); } return nbad == 2; } int main() { int N; cin >> N; if (N == 1) { puts("1"); return 0; } using Pti = Point2d; using Pt = Point2d; vector Pi(N); vector P(N); REP(i, N) { int x, y; cin >> x >> y; P.at(i) = Pt(x, y); Pi.at(i) = Pti(x, y); } // cin >> P; dbg(P); vector masks(N, vector(N)); vector> lines; REP(i, N) { auto c = P.at(i); REP(j, i) { auto dr = P.at(j) - P.at(i); lines.emplace_back(c, dr); } } vector pts{P.begin(), P.end()}; for (auto [c0, dr0] : lines) { for (auto [c1, dr1] : lines) { auto cp = lines_crosspoint(c0, dr0, c1, dr1); if (cp.has_value()) pts.push_back(cp.value()); } } for (auto &p : pts) { p.x = llround(p.x * 1e9) / 1e9; p.y = llround(p.y * 1e9) / 1e9; } pts = sort_unique(pts); const int V = pts.size(); using BS = bitset<(1 << 12)>; vector dp(V); REP(i, V) dp.at(i).set(0); vector mask(V, vector(V)); vector> graph_to(V); REP(i, V) REP(j, V) { const auto &from = pts.at(i); const auto &to = pts.at(j); REP(k, N) { auto p = P.at(k); bool match = false; if ((from - p).norm2() < 1e-5 or (to - p).norm2() < 1e-5) match = true; if ((from - p).norm2() < (to - from).norm2() and (to - p).norm2() < (to - from).norm2() and abs((to - from).det(p - from)) < 1e-5) match = true; if (match) mask[i][j] |= 1 << k; } int v = __builtin_popcount(mask[i][j]); if (v >= 2) graph_to.at(i).emplace_back(j, mask[i][j]); } FOR(d, 1, 6) { dbg(d); auto dpnxt = dp; REP(i, V) { for (auto [j, madd] : graph_to.at(i)) { // REP(j, V) { // int madd = mask.at(i).at(j); for (int s = dp.at(i)._Find_first(); s < 1 << N; s = dp.at(i)._Find_next(s)) { dpnxt.at(j)[s | madd] = 1; } } } dp = dpnxt; for (auto v : dp) { if (v[(1 << N) - 1]) { cout << d << endl; return 0; } } } puts("6"); }