#pragma once
#include "../divmod/lib.hpp"
#include "../shr/lib.hpp"
namespace tifa_libs {
namespace gcd_fps_impl_ {
template <poly_c poly_t>
using pttp = ptt<poly_t>;
template <poly_c poly_t>
struct matp {
poly_t a00, a01, a10, a11;
CEXPE matp() = default;
CEXP matp(u64 x00, u64 x01, u64 x10, u64 x11) NE : a00(1, x00), a01(1, x01), a10(1, x10), a11(1, x11) {}
CEXP matp(cT_(poly_t) a00, cT_(poly_t) a01, cT_(poly_t) a10, cT_(poly_t) a11) NE : a00(a00), a01(a01), a10(a10), a11(a11) {}
CEXP matp& operator*=(matp CR r) NE {
poly_t _00 = a00 * r.a00 + a01 * r.a10,
_01 = a00 * r.a01 + a01 * r.a11,
_10 = a10 * r.a00 + a11 * r.a10,
_11 = a10 * r.a01 + a11 * r.a11;
_00.strip(), _01.strip(), _10.strip(), _11.strip();
swap(_00, a00), swap(_01, a01), swap(_10, a10), swap(_11, a11);
return *this;
}
CEXP matp operator*(matp CR r) CNE { return matp(*this) *= r; }
friend CEXP pttp<poly_t> operator*(matp CR m, pttp<poly_t> CR a) NE {
poly_t b0 = m.a00 * a.first + m.a01 * a.second, b1 = m.a10 * a.first + m.a11 * a.second;
b0.strip(), b1.strip();
return {b0, b1};
}
};
template <poly_c poly_t>
CEXP void ngcd_(matp<poly_t>& m, pttp<poly_t>& p) NE {
auto [q, r] = divmod_fps(p.first, p.second);
auto b0 = m.a00 - m.a10 * q, b1 = m.a01 - m.a11 * q;
b0.strip(), b1.strip(), swap(b0, m.a10), swap(b1, m.a11), swap(b0, m.a00), swap(b1, m.a01);
p = {p.second, r};
}
template <poly_c poly_t>
CEXP auto hgcd_(pttp<poly_t> p) NE {
cu32 n = (u32)p.first.size(), m = (u32)p.second.size(), k = (n + 1) / 2;
if (m <= k) return matp<poly_t>(1, 0, 0, 1);
auto _ = hgcd_(pttp<poly_t>{shr_strip_fps(p.first, k), shr_strip_fps(p.second, k)});
p = _ * p;
if (p.second.size() <= k) return _;
ngcd_(_, p);
if (p.second.size() <= k) return _;
cu32 l = (u32)p.first.size() - 1, j = 2 * k - l;
return hgcd_(pttp<poly_t>{shr_strip_fps(p.first, j), shr_strip_fps(p.second, j)}) * _;
}
template <poly_c poly_t>
CEXP matp<poly_t> pgcd_(poly_t CR a, poly_t CR b) NE {
pttp<poly_t> p{a, b};
p.first.strip(), p.second.strip();
cu32 n = (u32)p.first.size(), m = (u32)p.second.size();
if (n < m) {
auto mat = pgcd_(p.second, p.first);
swap(mat.a00, mat.a01), swap(mat.a10, mat.a11);
return mat;
}
auto res = matp<poly_t>(1, 0, 0, 1);
while (true) {
auto _ = hgcd_(p);
if (p = _ * p; p.second.is_zero()) return _ * res;
if (ngcd_(_, p); p.second.is_zero()) return _ * res;
res = _ * res;
}
}
} // namespace gcd_fps_impl_
template <poly_c poly_t>
CEXP auto gcd_fps(poly_t CR f, poly_t CR g) NE {
ptt<poly_t> p(f, g);
if (p = gcd_fps_impl_::pgcd_(f, g) * p; !p.first.is_zero()) {
auto _ = p.first.back().inv();
p.first *= _;
}
return p.first;
}
} // namespace tifa_libs
#line 2 "src/fps/gcd/lib.hpp"
#line 2 "src/fps/divmod/lib.hpp"
#line 2 "src/fps/div/lib.hpp"
#line 2 "src/fps/inv/lib.hpp"
#line 2 "src/fps/ds/poly_c/lib.hpp"
#line 2 "src/util/strip/lib.hpp"
#line 2 "src/util/util/lib.hpp"
// https://github.com/Tiphereth-A/CP-lib
#include <bits/extc++.h>
// clang-format off
namespace tifa_libs {
#define CEXP constexpr
#define CEXPE constexpr explicit
#define CR const&
#define CP const*
#define PC *const
#define CPC const*const
#define TPN typename
#define NE noexcept
#define CNE const noexcept
#define ND [[nodiscard]]
#define cT_(...) std::conditional_t<sizeof(__VA_ARGS__) <= sizeof(size_t) * 2, __VA_ARGS__, __VA_ARGS__ CR>
// NOLINTNEXTLINE(misc-const-correctness)
#define flt_(T, i, l, r, ...) for (T i = (l), i##e = (r)__VA_OPT__(, ) __VA_ARGS__; i < i##e; ++i)
#define retif_(cond, if_true, ...) if cond return if_true __VA_OPT__(; else return __VA_ARGS__)
#ifdef ONLINE_JUDGE
#undef assert
#define assert(x) 42
#endif
using namespace std::ranges;
using namespace std::literals;
template <class T>
CEXP T abs(T x) NE { retif_((x < 0), -x, x); }
} // namespace tifa_libs
// clang-format on
#line 4 "src/util/strip/lib.hpp"
namespace tifa_libs {
// pred(x) == true ==> drop
template <common_range R, class F>
CEXP auto lstrip_view(R CR range, F&& pred) NE {
auto v = range | views::drop_while(std::forward<F>(pred));
return subrange{begin(v), end(v)};
}
// pred(x) == true ==> drop
template <common_range R, class F>
CEXP auto rstrip_view(R CR range, F&& pred) NE {
auto v = range | views::reverse | views::drop_while(std::forward<F>(pred));
return subrange{end(v).base(), begin(v).base()};
}
// pred(x) == true ==> drop
template <common_range R, class F>
CEXP auto strip_view(R CR range, F&& pred) NE {
auto v = range | views::drop_while(std::forward<F>(pred)) | views::reverse | views::drop_while(std::forward<F>(pred));
return subrange{end(v).base(), begin(v).base()};
}
} // namespace tifa_libs
#line 2 "src/util/traits/others/lib.hpp"
// clang-format off
#line 2 "src/util/alias/others/lib.hpp"
#line 2 "src/util/consts/lib.hpp"
#line 2 "src/util/alias/num/lib.hpp"
#line 4 "src/util/alias/num/lib.hpp"
// clang-format off
namespace tifa_libs {
#define mk0_(w, t) using w = t; using c##w = const t
#define mk_(w, t) mk0_(w, t); CEXP w operator""_##w(unsigned long long x) NE { return (w)x; }
mk_(i8, int8_t) mk_(u8, uint8_t) mk_(i16, int16_t) mk_(u16, uint16_t) mk_(i32, int32_t) mk_(u32, uint32_t) mk_(i64, int64_t) mk_(u64, uint64_t) mk_(isz, ssize_t) mk_(usz, size_t) mk_(chr, char) mk_(schr, signed char) mk_(uchr, unsigned char) mk_(sint, signed) mk_(uint, unsigned);
mk0_(i128, __int128_t); mk0_(u128, __uint128_t); mk0_(f32, float); mk0_(f64, double); mk0_(f128, long double);
#undef mk0_
#undef mk_
} // namespace tifa_libs
// clang-format on
#line 4 "src/util/consts/lib.hpp"
// clang-format off
namespace tifa_libs {
using std::numbers::pi_v;
template <std::floating_point FP>
inline FP eps_v = std::sqrt(std::numeric_limits<FP>::epsilon());
template <std::floating_point FP>
CEXP void set_eps(FP v) NE { eps_v<FP> = v; }
CEXP u32 TIME = ((__TIME__[0] & 15) << 20) | ((__TIME__[1] & 15) << 16) | ((__TIME__[3] & 15) << 12) | ((__TIME__[4] & 15) << 8) | ((__TIME__[6] & 15) << 4) | (__TIME__[7] & 15);
CEXP auto STR2U16 = [] { std::array<u32, 65536> table{}; table.fill(-1_u32); flt_ (u32, i, 48, 58) flt_ (u32, j, 48, 58) table[i << 8 | j] = (j & 15) * 10 + (i & 15); return table; }();
inline const auto fn_0 = [](auto&&...) NE {};
inline const auto fn_is0 = [](auto x) NE { return x == 0; };
} // namespace tifa_libs
// clang-format on
#line 4 "src/util/alias/others/lib.hpp"
namespace tifa_libs {
template <class T>
struct chash {
CEXP static u64 C = u64(pi_v<f128> * 2e18) | 71;
CEXP u64 operator()(T x) CNE { return __builtin_bswap64(((u64)x ^ TIME) * C); }
};
// clang-format off
#define mk_(w, t) using w = t; using c##w = const t;
mk_(strn, std::string) mk_(strnv, std::string_view)
#undef mk_
template <class T> struct edge_t { T w; u32 u, v; CEXP auto operator<=>(edge_t CR) const = default; }; template <class T> using cedge_t = const edge_t<T>;
template <class T> struct pt3 { T _0, _1, _2; CEXP auto operator<=>(pt3 CR) const = default; }; template <class T> using cpt3 = const pt3<T>;
template <class T> struct pt4 { T _0, _1, _2, _3; CEXP auto operator<=>(pt4 CR) const = default; }; template <class T> using cpt4 = const pt4<T>;
#define mkT_(w, t, ...) template <class T> using w = t __VA_OPT__(, ) __VA_ARGS__; template <class T> using c##w = const t __VA_OPT__(, ) __VA_ARGS__;
mkT_(ptt, std::pair<T, T>) mkT_(alc, std::pmr::polymorphic_allocator<T>) mkT_(vec, std::vector<T>) mkT_(vvec, vec<vec<T>>) mkT_(v3ec, vvec<vec<T>>) mkT_(vecpt, vec<ptt<T>>) mkT_(vvecpt, vvec<ptt<T>>) mkT_(ptvec, ptt<vec<T>>) mkT_(ptvvec, ptt<vvec<T>>)
#undef mkT_
template <class T> using itl = std ::initializer_list<T>;
template <class T, usz ext = std::dynamic_extent> using spn = std::span<T const, ext>;
template <class T, usz N> using arr = std::array<T, N>; template <class T, usz N> using carr = std::array<const T, N>;
template <class U, class T> using vecp = vec<std::pair<U, T>>; template <class U, class T> using vvecp = vvec<std::pair<U, T>>;
template <class U, class T> using vvecp = vvec<std::pair<U, T>>; template <class U, class T> using vvvecp = vvec<vvec<std::pair<U, T>>>;
#ifdef PB_DS_ASSOC_CNTNR_HPP
template <class T, class C = std::less<T>> using set = __gnu_pbds::tree<T, __gnu_pbds::null_type, C>;
template <class K, class V, class C = std::less<K>> using map = __gnu_pbds::tree<K, V, C>;
// hset<u64> s({}, {}, {}, {}, {1<<16});
template <class T, class HF = chash<T>> using hset = __gnu_pbds::gp_hash_table<T, __gnu_pbds::null_type, HF>;
// hmap<u64, int> s({}, {}, {}, {}, {1<<16});
template <class K, class V, class HF = chash<K>> using hmap = __gnu_pbds::gp_hash_table<K, V, HF>;
#else
using std::set, std::map;
template <class T, class HF = chash<T>> using hset = std::unordered_set<T, HF>;
template <class K, class V, class HF = chash<K>> using hmap = std::unordered_map<K, V, HF>;
#endif
#ifdef PB_DS_PRIORITY_QUEUE_HPP
template <class T, class C = std::less<T>> using pq = __gnu_pbds::priority_queue<T, C>;
#else
template <class T, class C = std::less<T>> using pq = std::priority_queue<T, vec<T>, C>;
#endif
template <class T> using pqg = pq<T, std::greater<T>>;
// clang-format on
#define mk1_(V, A, T) using V##A = V<T>;
#define mk_(V, A, T) mk1_(V, A, T) mk1_(c##V, A, T)
#define mk(A, T) mk_(edge_t, A, T) mk_(ptt, A, T) mk_(pt3, A, T) mk_(pt4, A, T) mk_(vec, A, T) mk_(vvec, A, T) mk_(v3ec, A, T) mk_(vecpt, A, T) mk_(vvecpt, A, T) mk_(ptvec, A, T) mk_(ptvvec, A, T) mk1_(spn, A, T) mk1_(itl, A, T)
mk(b, bool) mk(c, chr) mk(i, i32) mk(u, u32) mk(ii, i64) mk(uu, u64) mk(t, isz) mk(z, usz) mk(f, f32) mk(d, f64) mk(s, strn);
#undef mk
#undef mk_
#undef mk1_
} // namespace tifa_libs
#line 4 "src/util/traits/others/lib.hpp"
namespace tifa_libs {
//! only for template without non-type argument
template <class, template <class...> class> CEXP bool specialized_from_v = false;
template <template <class...> class T, class... Args> CEXP bool specialized_from_v<T<Args...>, T> = true;
static_assert(specialized_from_v<vecu, std::vector>);
template <class T> concept container_c = common_range<T> && !std::is_array_v<std::remove_cvref_t<T>> && !std::same_as<std::remove_cvref_t<T>, strn> && !std::same_as<std::remove_cvref_t<T>, strnv>;
template <class T> concept istream_c = std::derived_from<T, std::istream> || std::derived_from<T, std::wistream> || requires(T is) { is.peek(); };
template <class T> concept ostream_c = std::derived_from<T, std::ostream> || std::derived_from<T, std::wostream> || requires(T os) { os.flush(); };
} // namespace tifa_libs
// clang-format on
#line 5 "src/fps/ds/poly_c/lib.hpp"
namespace tifa_libs {
// clang-format off
enum class CCORE : u8 { FFT_R2, NTT3, NTT };
// clang-format on
namespace poly_impl_ {
template <class ccore>
requires requires(ccore cc, vec<TPN ccore::val_t> l, vec<TPN ccore::val_t> r, u32 sz) {
{ ccore::ct_cat } -> std::same_as<CCORE CR>;
cc.conv(l, r), cc.conv(l, r, sz);
}
struct poly : vec<TPN ccore::val_t> {
using ccore_t = ccore;
using val_t = ccore_t::val_t;
using data_t = vec<val_t>;
static inline ccore_t conv_core;
CEXPE poly(u32 sz = 1, cT_(val_t) val = val_t{}) NE : data_t(sz, val) {}
CEXP poly(TPN data_t::const_iterator begin, TPN data_t::const_iterator end) NE : data_t(begin, end) {}
CEXP poly(data_t CR v) NE : data_t(v) {}
CEXP poly(data_t&& v) NE : data_t(std::move(v)) {}
CEXP poly(itl<val_t> v) NE : data_t(v) {}
CEXP poly(common_range auto CR v) NE : data_t(begin(v), end(v)) {}
friend CEXP auto& operator>>(istream_c auto& is, poly& poly) NE {
for (auto& val : poly) is >> val;
return is;
}
friend CEXP auto& operator<<(ostream_c auto& os, poly CR poly) NE {
retif_((!poly.size()) [[unlikely]], os);
flt_ (u32, i, 1, (u32)poly.size()) os << poly[i - 1] << ' ';
return os << poly.back();
}
ND CEXP bool is_zero() CNE {
for (auto&& i : *this)
if (i != 0) return false;
return true;
}
CEXP val_t operator()(val_t x) CNE {
val_t ans = 0;
for (u32 i = data_t::size() - 1; ~i; --i) ans = ans * x + data_t::data()[i];
return ans;
}
template <class F>
requires requires(F f, u32 idx, val_t& val) { f(idx, val); }
CEXP void apply_range(u32 l, u32 r, F&& f) NE {
assert(l < r && r <= data_t::size());
flt_ (u32, i, l, r) f(i, data_t::data()[i]);
}
template <class F>
CEXP void apply(F&& f) NE { apply_range(0, (u32)data_t::size(), std::forward<F>(f)); }
ND CEXP poly pre(u32 sz) CNE {
if (sz <= this->size()) return {this->begin(), this->begin() + sz};
poly _ = *this;
_.resize(sz);
return _;
}
CEXP void strip() NE {
auto [_, r] = rstrip_view(*this, [](cT_(val_t) x) NE { return x.val() == 0; });
if (data_t::erase(r, this->end()); data_t::empty()) data_t::push_back(val_t(0));
}
friend poly stripped(poly CR p) NE {
poly ret(rstrip_view(p, [](cT_(val_t) x) NE { return x.val() == 0; }));
if (ret.empty()) return {0};
return ret;
}
CEXP void reverse(u32 n = 0) NE { std::ranges::reverse(data_t::begin(), data_t::begin() + (n ? n : (u32)data_t::size())); }
CEXP void conv(poly CR r, u32 ans_size = 0) NE { conv_core.conv(*this, r, ans_size); }
CEXP poly operator-() CNE {
poly ret = *this;
ret.apply([](u32, auto& v) NE { v = -v; });
return ret;
}
friend CEXP poly operator+(poly p, val_t c) NE {
p[0] += c;
return p;
}
friend CEXP poly operator+(val_t c, poly CR p) NE { return p + c; }
friend CEXP poly operator-(poly p, val_t c) NE {
p[0] -= c;
return p;
}
friend CEXP poly operator-(val_t c, poly CR p) NE { return p - c; }
CEXP poly& operator*=(val_t c) NE {
apply([&c](u32, auto& v) NE { v *= c; });
return *this;
}
friend CEXP poly operator*(poly p, val_t c) NE { return p *= c; }
friend CEXP poly operator*(val_t c, poly p) NE { return p *= c; }
CEXP poly& operator+=(poly CR r) NE {
retif_((r.empty()) [[unlikely]], *this);
data_t::resize(max(data_t::size(), r.size())), apply_range(0, (u32)r.size(), [&r](u32 i, auto& v) NE { v += r[i]; });
return *this;
}
friend CEXP poly operator+(poly l, poly CR r) NE { return l += r; }
CEXP poly& operator-=(poly CR r) NE {
retif_((r.empty()) [[unlikely]], *this);
data_t::resize(max(data_t::size(), r.size()));
apply_range(0, (u32)r.size(), [&r](u32 i, auto& v) NE { v -= r[i]; });
return *this;
}
friend CEXP poly operator-(poly l, poly CR r) NE { return l -= r; }
CEXP poly& operator*=(poly CR r) NE {
if (r.empty()) {
data_t::resize(1), *data_t::data() = 0;
return *this;
}
conv(r);
return *this;
}
friend CEXP poly operator*(poly l, poly CR r) NE { return l *= r; }
CEXP auto operator<=>(poly CR r) CNE {
auto l_ = stripped(*this), r_ = stripped(r);
if (l_.size() != r_.size()) return l_.size() <=> r_.size();
return std::lexicographical_compare_three_way(l_.rbegin(), l_.rend(), r_.rbegin(), r_.rend());
}
CEXP bool operator==(poly CR r) CNE { return std::is_eq(*this <=> r); }
};
} // namespace poly_impl_
template <class T>
concept poly_c = std::same_as<T, poly_impl_::poly<TPN T::ccore_t>>;
} // namespace tifa_libs
#line 4 "src/fps/inv/lib.hpp"
namespace tifa_libs {
template <poly_c poly_t>
CEXP auto inv_fps(poly_t CR p, u32 n = 0) NE {
if (assert(p[0] != 0); !n) n = (u32)p.size();
poly_t a{p[0].inv()};
for (u32 i = 1; i < n; i *= 2) a = (a * 2 - (a * a * p).pre(i * 2)).pre(i * 2);
return a.pre(n);
}
} // namespace tifa_libs
#line 4 "src/fps/div/lib.hpp"
namespace tifa_libs {
template <poly_c poly_t>
CEXP auto div_fps(poly_t p, poly_t q) NE {
cu32 n = (u32)p.size(), m = (u32)q.size();
if (n < m) return poly_t{};
p.reverse(), q.reverse();
q.resize(n - m + 1), p.conv(inv_fps(q));
p.resize(n - m + 1), p.reverse();
return p;
}
} // namespace tifa_libs
#line 4 "src/fps/divmod/lib.hpp"
namespace tifa_libs {
template <poly_c poly_t>
CEXP auto divmod_fps(poly_t CR p, poly_t CR q) NE {
cu32 n = (u32)p.size(), m = (u32)q.size();
if (n < m) return std::make_pair(poly_t{}, p);
auto d = div_fps(p, q);
d.strip();
auto r = d;
r.conv(q), r.resize(m - 1), (r = p - r).resize(m - 1), r.strip();
return std::make_pair(d, r);
}
} // namespace tifa_libs
#line 2 "src/fps/shr/lib.hpp"
#line 4 "src/fps/shr/lib.hpp"
namespace tifa_libs {
CEXP auto shr_fps(poly_c auto CR p, usz x) NE {
retif_((!x) [[unlikely]], p);
auto _ = p;
fill(std::shift_left(begin(_), end(_), (isz)x), end(_), 0);
return _;
}
CEXP auto shr_strip_fps(poly_c auto CR p, usz x) NE {
auto _ = p;
_.erase(std::shift_left(begin(_), end(_), (isz)x), end(_));
return _;
}
} // namespace tifa_libs
#line 5 "src/fps/gcd/lib.hpp"
namespace tifa_libs {
namespace gcd_fps_impl_ {
template <poly_c poly_t>
using pttp = ptt<poly_t>;
template <poly_c poly_t>
struct matp {
poly_t a00, a01, a10, a11;
CEXPE matp() = default;
CEXP matp(u64 x00, u64 x01, u64 x10, u64 x11) NE : a00(1, x00), a01(1, x01), a10(1, x10), a11(1, x11) {}
CEXP matp(cT_(poly_t) a00, cT_(poly_t) a01, cT_(poly_t) a10, cT_(poly_t) a11) NE : a00(a00), a01(a01), a10(a10), a11(a11) {}
CEXP matp& operator*=(matp CR r) NE {
poly_t _00 = a00 * r.a00 + a01 * r.a10,
_01 = a00 * r.a01 + a01 * r.a11,
_10 = a10 * r.a00 + a11 * r.a10,
_11 = a10 * r.a01 + a11 * r.a11;
_00.strip(), _01.strip(), _10.strip(), _11.strip();
swap(_00, a00), swap(_01, a01), swap(_10, a10), swap(_11, a11);
return *this;
}
CEXP matp operator*(matp CR r) CNE { return matp(*this) *= r; }
friend CEXP pttp<poly_t> operator*(matp CR m, pttp<poly_t> CR a) NE {
poly_t b0 = m.a00 * a.first + m.a01 * a.second, b1 = m.a10 * a.first + m.a11 * a.second;
b0.strip(), b1.strip();
return {b0, b1};
}
};
template <poly_c poly_t>
CEXP void ngcd_(matp<poly_t>& m, pttp<poly_t>& p) NE {
auto [q, r] = divmod_fps(p.first, p.second);
auto b0 = m.a00 - m.a10 * q, b1 = m.a01 - m.a11 * q;
b0.strip(), b1.strip(), swap(b0, m.a10), swap(b1, m.a11), swap(b0, m.a00), swap(b1, m.a01);
p = {p.second, r};
}
template <poly_c poly_t>
CEXP auto hgcd_(pttp<poly_t> p) NE {
cu32 n = (u32)p.first.size(), m = (u32)p.second.size(), k = (n + 1) / 2;
if (m <= k) return matp<poly_t>(1, 0, 0, 1);
auto _ = hgcd_(pttp<poly_t>{shr_strip_fps(p.first, k), shr_strip_fps(p.second, k)});
p = _ * p;
if (p.second.size() <= k) return _;
ngcd_(_, p);
if (p.second.size() <= k) return _;
cu32 l = (u32)p.first.size() - 1, j = 2 * k - l;
return hgcd_(pttp<poly_t>{shr_strip_fps(p.first, j), shr_strip_fps(p.second, j)}) * _;
}
template <poly_c poly_t>
CEXP matp<poly_t> pgcd_(poly_t CR a, poly_t CR b) NE {
pttp<poly_t> p{a, b};
p.first.strip(), p.second.strip();
cu32 n = (u32)p.first.size(), m = (u32)p.second.size();
if (n < m) {
auto mat = pgcd_(p.second, p.first);
swap(mat.a00, mat.a01), swap(mat.a10, mat.a11);
return mat;
}
auto res = matp<poly_t>(1, 0, 0, 1);
while (true) {
auto _ = hgcd_(p);
if (p = _ * p; p.second.is_zero()) return _ * res;
if (ngcd_(_, p); p.second.is_zero()) return _ * res;
res = _ * res;
}
}
} // namespace gcd_fps_impl_
template <poly_c poly_t>
CEXP auto gcd_fps(poly_t CR f, poly_t CR g) NE {
ptt<poly_t> p(f, g);
if (p = gcd_fps_impl_::pgcd_(f, g) * p; !p.first.is_zero()) {
auto _ = p.first.back().inv();
p.first *= _;
}
return p.first;
}
} // namespace tifa_libs
src/fps/gcd/lib.hpp