test/yosupo-judge/find_linear_recurrence/main.test.cpp
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Code
#define PROBLEM "https://judge.yosupo.jp/problem/find_linear_recurrence"
#include "Mylib/IO/input_vector.cpp"
#include "Mylib/IO/join.cpp"
#include "Mylib/Math/berlekamp_massey.cpp"
#include "Mylib/Number/Mint/mint.cpp"
namespace hl = haar_lib;
constexpr int mod = 998244353;
using mint = hl::modint<mod>;
int main() {
std::cin.tie(0);
std::ios::sync_with_stdio(false);
int N;
std::cin >> N;
auto a = hl::input_vector<mint>(N);
auto c = berlekamp_massey(a);
std::cout << c.size() << "\n"
<< hl::join(c.begin(), c.end()) << "\n";
return 0;
}
#line 1 "test/yosupo-judge/find_linear_recurrence/main.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/find_linear_recurrence"
#line 2 "Mylib/IO/input_vector.cpp"
#include <iostream>
#include <vector>
namespace haar_lib {
template <typename T>
std::vector<T> input_vector(int N) {
std::vector<T> ret(N);
for (int i = 0; i < N; ++i) std::cin >> ret[i];
return ret;
}
template <typename T>
std::vector<std::vector<T>> input_vector(int N, int M) {
std::vector<std::vector<T>> ret(N);
for (int i = 0; i < N; ++i) ret[i] = input_vector<T>(M);
return ret;
}
} // namespace haar_lib
#line 3 "Mylib/IO/join.cpp"
#include <sstream>
#include <string>
namespace haar_lib {
template <typename Iter>
std::string join(Iter first, Iter last, std::string delim = " ") {
std::stringstream s;
for (auto it = first; it != last; ++it) {
if (it != first) s << delim;
s << *it;
}
return s.str();
}
} // namespace haar_lib
#line 3 "Mylib/Math/berlekamp_massey.cpp"
namespace haar_lib {
template <typename T>
std::vector<T> berlekamp_massey(const std::vector<T> &s) {
const int N = s.size();
std::vector<T> C = {1}, B = {1};
int L = 0, m = 1;
T b = 1;
for (int n = 0; n < N; ++n) {
T d = s[n];
for (size_t i = 1; i < C.size(); ++i) d += C[i] * s[n - i];
if (d == 0) {
m += 1;
} else if (2 * L <= n) {
auto temp = C;
if (C.size() < B.size() + m) C.resize(B.size() + m);
const T t = d / b;
for (int i = 0; i < (int) B.size(); ++i) C[i + m] -= t * B[i];
L = n + 1 - L;
B = temp;
b = d;
m = 1;
} else {
if (C.size() < B.size() + m) C.resize(B.size() + m);
const T t = d / b;
for (int i = 0; i < (int) B.size(); ++i) C[i + m] -= t * B[i];
m += 1;
}
}
std::vector<T> ret(L);
for (int i = 0; i < L; ++i) ret[i] = -C[i + 1];
return ret;
}
} // namespace haar_lib
#line 3 "Mylib/Number/Mint/mint.cpp"
#include <utility>
namespace haar_lib {
template <int32_t M>
class modint {
uint32_t val_;
public:
constexpr static auto mod() { return M; }
constexpr modint() : val_(0) {}
constexpr modint(int64_t n) {
if (n >= M)
val_ = n % M;
else if (n < 0)
val_ = n % M + M;
else
val_ = n;
}
constexpr auto &operator=(const modint &a) {
val_ = a.val_;
return *this;
}
constexpr auto &operator+=(const modint &a) {
if (val_ + a.val_ >= M)
val_ = (uint64_t) val_ + a.val_ - M;
else
val_ += a.val_;
return *this;
}
constexpr auto &operator-=(const modint &a) {
if (val_ < a.val_) val_ += M;
val_ -= a.val_;
return *this;
}
constexpr auto &operator*=(const modint &a) {
val_ = (uint64_t) val_ * a.val_ % M;
return *this;
}
constexpr auto &operator/=(const modint &a) {
val_ = (uint64_t) val_ * a.inv().val_ % M;
return *this;
}
constexpr auto operator+(const modint &a) const { return modint(*this) += a; }
constexpr auto operator-(const modint &a) const { return modint(*this) -= a; }
constexpr auto operator*(const modint &a) const { return modint(*this) *= a; }
constexpr auto operator/(const modint &a) const { return modint(*this) /= a; }
constexpr bool operator==(const modint &a) const { return val_ == a.val_; }
constexpr bool operator!=(const modint &a) const { return val_ != a.val_; }
constexpr auto &operator++() {
*this += 1;
return *this;
}
constexpr auto &operator--() {
*this -= 1;
return *this;
}
constexpr auto operator++(int) {
auto t = *this;
*this += 1;
return t;
}
constexpr auto operator--(int) {
auto t = *this;
*this -= 1;
return t;
}
constexpr static modint pow(int64_t n, int64_t p) {
if (p < 0) return pow(n, -p).inv();
int64_t ret = 1, e = n % M;
for (; p; (e *= e) %= M, p >>= 1)
if (p & 1) (ret *= e) %= M;
return ret;
}
constexpr static modint inv(int64_t a) {
int64_t b = M, u = 1, v = 0;
while (b) {
int64_t t = a / b;
a -= t * b;
std::swap(a, b);
u -= t * v;
std::swap(u, v);
}
u %= M;
if (u < 0) u += M;
return u;
}
constexpr static auto frac(int64_t a, int64_t b) { return modint(a) / modint(b); }
constexpr auto pow(int64_t p) const { return pow(val_, p); }
constexpr auto inv() const { return inv(val_); }
friend constexpr auto operator-(const modint &a) { return modint(M - a.val_); }
friend constexpr auto operator+(int64_t a, const modint &b) { return modint(a) + b; }
friend constexpr auto operator-(int64_t a, const modint &b) { return modint(a) - b; }
friend constexpr auto operator*(int64_t a, const modint &b) { return modint(a) * b; }
friend constexpr auto operator/(int64_t a, const modint &b) { return modint(a) / b; }
friend std::istream &operator>>(std::istream &s, modint &a) {
s >> a.val_;
return s;
}
friend std::ostream &operator<<(std::ostream &s, const modint &a) {
s << a.val_;
return s;
}
template <int N>
static auto div() {
static auto value = inv(N);
return value;
}
explicit operator int32_t() const noexcept { return val_; }
explicit operator int64_t() const noexcept { return val_; }
};
} // namespace haar_lib
#line 7 "test/yosupo-judge/find_linear_recurrence/main.test.cpp"
namespace hl = haar_lib;
constexpr int mod = 998244353;
using mint = hl::modint<mod>;
int main() {
std::cin.tie(0);
std::ios::sync_with_stdio(false);
int N;
std::cin >> N;
auto a = hl::input_vector<mint>(N);
auto c = berlekamp_massey(a);
std::cout << c.size() << "\n"
<< hl::join(c.begin(), c.end()) << "\n";
return 0;
}
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Input vector
(Mylib/IO/input_vector.cpp)