多项式模板(dls)

FFT

#include <bits/stdc++.h>
#define rep(i, a, b) for (int i = a; i < (int)b; i++)

using namespace std;

typedef double db;
typedef long long ll;
const int FFT_MAXN = 262144, N = 301000;
const db pi = acos(-1.);

struct cp
{
	db a, b;
	cp operator+(const cp&y) const{return (cp){a + y.a, b + y.b};}
	cp operator-(const cp&y) const{return (cp){a - y.a, b - y.b};}
	cp operator*(const cp&y) const{return (cp){a * y.a - b * y.b, a * y.b + b * y.a};}
	cp operator!() const{return (cp){a, -b};}
}nw[FFT_MAXN+1];
int bitrev[FFT_MAXN];
void dft(cp *a, int n, int flag = 1)
{
	int d = 0;
	while((1 << d) * n != FFT_MAXN) d++;
	rep(i, 0, n) if (i < (bitrev[i] >> d)) swap(a[i], a[bitrev[i] >> d]);
	for (int l = 2; l <= n; l <<= 1)
	{
		int del = FFT_MAXN / l * flag;
		for (int i = 0; i < n; i += l)
		{
			cp *le = a + i, *ri = a + i + (l >> 1), *w = flag == 1 ? nw : nw + FFT_MAXN;
			rep(k, 0, l >> 1)
			{
				cp ne = *ri * *w;
				*ri = *le - ne, *le = *le + ne;
				le++, ri++, w += del;
			}
		}
	}
	if (flag != 1) rep(i, 0, n) a[i].a /= n, a[i].b /= n;
}

void fft_init()
{
	int L = 0;
	while((1 << L) != FFT_MAXN) L++;
	bitrev[0] = 0;
	rep(i, 1, FFT_MAXN) bitrev[i] = bitrev[i>>1]>>1|((i&1)<<(L-1));
	nw[0] = nw[FFT_MAXN] = (cp){1, 0};
	rep(i, 0, FFT_MAXN+1) nw[i] = (cp){cos(2*pi/FFT_MAXN*i), sin(2*pi/FFT_MAXN*i)};
}

void convo(db *a, int n, db *b, int m, db *c)
{
	static cp f[FFT_MAXN>>1], g[FFT_MAXN>>1], t[FFT_MAXN>>1];
	int N = 2;
	while(N <= n + m) N <<= 1;
	rep(i, 0, N)
	{
		if (i & 1)
		{
			f[i>>1].b = (i <= n) ? a[i] : 0.0;
			g[i>>1].b = (i <= m) ? b[i] : 0.0;
		}
		else
		{
			f[i>>1].a = (i <= n) ? a[i] : 0.0;
			g[i>>1].a = (i <= m) ? b[i] : 0.0;
		}
	}
	dft(f, N >> 1);
	dft(g, N >> 1);
	int del = FFT_MAXN / (N >> 1);
	cp qua = (cp){0, 0.25}, one = (cp){1, 0}, four = (cp){4, 0}, *w = nw;
	rep(i, 0, N >> 1)
	{
		int j = i ? (N>>1)-i : 0;
		t[i] = (four * !(f[j]*g[j]) - (!f[j] - f[i]) * (!g[j] - g[i]) * (one+ *w)) * qua;
		w += del;
	}
	dft(t, N >> 1, -1);
	rep(i, 0, n + m + 1)
	c[i] = (i&1) ? t[i>>1].a : t[i>>1].b;
}

int n;
db q[N], f[N], g[N], h1[N], h2[N];
int main()
{
	fft_init();
	scanf("%d", &n);
	for (int i = 1; i <= n; i++)
		scanf("%lf", &q[i]);
	for (int i = 1; i <= n; i++)
		f[i] = q[i], g[i] = (db)1 / i / i;
	convo(f, n, g, n, h1);
	for (int i = 0; i <= n; i++)
		f[i] = q[n - i];
	convo(f, n, g, n, h2);
	for (int i = 1; i <= n; i++)
	{
		db ans = h1[i] - h2[n - i];
		printf("%.10lf\n", ans);
	}
	return 0;
}

NTT

const int md = 998244353;

inline void add(int &x, int y) {
  x += y;
  if (x >= md) {
    x -= md;
  }
}

inline void sub(int &x, int y) {
  x -= y;
  if (x < 0) {
    x += md;
  }
}

inline int mul(int x, int y) {
  return (long long) x * y % md;
}

inline int power(int x, int y) {
  int res = 1;
  for (; y; y >>= 1, x = mul(x, x)) {
    if (y & 1) {
      res = mul(res, x);
    }
  }
  return res;
}

inline int inv(int a) {
  a %= md;
  if (a < 0) {
    a += md;
  }
  int b = md, u = 0, v = 1;
  while (a) {
    int t = b / a;
    b -= t * a;
    swap(a, b);
    u -= t * v;
    swap(u, v);
  }
  if (u < 0) {
    u += md;
  }
  return u;
}

namespace ntt {
int base = 1, root = -1, max_base = -1;
vector<int> rev = {0, 1}, roots = {0, 1};

void init() {
  int temp = md - 1;
  max_base = 0;
  while (temp % 2 == 0) {
    temp >>= 1;
    ++max_base;
  }
  root = 2;
  while (true) {
    if (power(root, 1 << max_base) == 1 && power(root, 1 << (max_base - 1)) != 1) {
      break;
    }
    ++root;
  }
}

void ensure_base(int nbase) {
  if (max_base == -1) {
    init();
  }
  if (nbase <= base) {
    return;
  }
  assert(nbase <= max_base);
  rev.resize(1 << nbase);
  for (int i = 0; i < 1 << nbase; ++i) {
    rev[i] = (rev[i >> 1] >> 1) | ((i & 1) << (nbase - 1));
  }
  roots.resize(1 << nbase);
  while (base < nbase) {
    int z = power(root, 1 << (max_base - 1 - base));
    for (int i = 1 << (base - 1); i < 1 << base; ++i) {
      roots[i << 1] = roots[i];
      roots[i << 1 | 1] = mul(roots[i], z);
    }
    ++base;
  }
}

void dft(vector<int> &a) {
  int n = a.size(), zeros = __builtin_ctz(n);
  ensure_base(zeros);
  int shift = base - zeros;
  for (int i = 0; i < n; ++i) {
    if (i < rev[i] >> shift) {
      swap(a[i], a[rev[i] >> shift]);
    }
  }
  for (int i = 1; i < n; i <<= 1) {
    for (int j = 0; j < n; j += i << 1) {
      for (int k = 0; k < i; ++k) {
        int x = a[j + k], y = mul(a[j + k + i], roots[i + k]);
        a[j + k] = (x + y) % md;
        a[j + k + i] = (x + md - y) % md;
      }
    }
  }
}

vector<int> multiply(vector<int> a, vector<int> b) {
  int need = a.size() + b.size() - 1, nbase = 0;
  while (1 << nbase < need) {
    ++nbase;
  }
  ensure_base(nbase);
  int sz = 1 << nbase;
  a.resize(sz);
  b.resize(sz);
  bool equal = a == b;
  dft(a);
  if (equal) {
    b = a;
  } else {
    dft(b);
  }
  int inv_sz = inv(sz);
  for (int i = 0; i < sz; ++i) {
    a[i] = mul(mul(a[i], b[i]), inv_sz);
  }
  reverse(a.begin() + 1, a.end());
  dft(a);
  a.resize(need);
  return a;
}

vector<int> inverse(vector<int> a) {
  int n = a.size(), m = (n + 1) >> 1;
  if (n == 1) {
    return vector<int>(1, inv(a[0]));
  } else {
    vector<int> b = inverse(vector<int>(a.begin(), a.begin() + m));
    int need = n << 1, nbase = 0;
    while (1 << nbase < need) {
      ++nbase;
    }
    ensure_base(nbase);
    int sz = 1 << nbase;
    a.resize(sz);
    b.resize(sz);
    dft(a);
    dft(b);
    int inv_sz = inv(sz);
    for (int i = 0; i < sz; ++i) {
      a[i] = mul(mul(md + 2 - mul(a[i], b[i]), b[i]), inv_sz);
    }
    reverse(a.begin() + 1, a.end());
    dft(a);
    a.resize(n);
    return a;
  }
}
}

using ntt::multiply;
using ntt::inverse;

vector<int>& operator += (vector<int> &a, const vector<int> &b) {
  if (a.size() < b.size()) {
    a.resize(b.size());
  }
  for (int i = 0; i < b.size(); ++i) {
    add(a[i], b[i]);
  }
  return a;
}

vector<int> operator + (const vector<int> &a, const vector<int> &b) {
  vector<int> c = a;
  return c += b;
}

vector<int>& operator -= (vector<int> &a, const vector<int> &b) {
  if (a.size() < b.size()) {
    a.resize(b.size());
  }
  for (int i = 0; i < b.size(); ++i) {
    sub(a[i], b[i]);
  }
  return a;
}

vector<int> operator - (const vector<int> &a, const vector<int> &b) {
  vector<int> c = a;
  return c -= b;
}

vector<int>& operator *= (vector<int> &a, const vector<int> &b) {
  if (min(a.size(), b.size()) < 128) {
    vector<int> c = a;
    a.assign(a.size() + b.size() - 1, 0);
    for (int i = 0; i < c.size(); ++i) {
      for (int j = 0; j < b.size(); ++j) {
        add(a[i + j], mul(c[i], b[j]));
      }
    }
  } else {
    a = multiply(a, b);
  }
  return a;
}

vector<int> operator * (const vector<int> &a, const vector<int> &b) {
  vector<int> c = a;
  return c *= b;
}

vector<int>& operator /= (vector<int> &a, const vector<int> &b) {
  int n = a.size(), m = b.size();
  if (n < m) {
    a.clear();
  } else {
    vector<int> c = b;
    reverse(a.begin(), a.end());
    reverse(c.begin(), c.end());
    c.resize(n - m + 1);
    a *= inverse(c);
    a.erase(a.begin() + n - m + 1, a.end());
    reverse(a.begin(), a.end());
  }
  return a;
}

vector<int> operator / (const vector<int> &a, const vector<int> &b) {
  vector<int> c = a;
  return c /= b;
}

vector<int>& operator %= (vector<int> &a, const vector<int> &b) {
  int n = a.size(), m = b.size();
  if (n >= m) {
    vector<int> c = (a / b) * b;
    a.resize(m - 1);
    for (int i = 0; i < m - 1; ++i) {
      sub(a[i], c[i]);
    }
  }
  return a;
}

vector<int> operator % (const vector<int> &a, const vector<int> &b) {
  vector<int> c = a;
  return c %= b;
}

vector<int> derivative(const vector<int> &a) {
  int n = a.size();
  vector<int> b(n - 1);
  for (int i = 1; i < n; ++i) {
    b[i - 1] = mul(a[i], i);
  }
  return b;
}

vector<int> primitive(const vector<int> &a) {
  int n = a.size();
  vector<int> b(n + 1), invs(n + 1);
  for (int i = 1; i <= n; ++i) {
    invs[i] = i == 1 ? 1 : mul(md - md / i, invs[md % i]);
    b[i] = mul(a[i - 1], invs[i]);
  }
  return b;
}

vector<int> logarithm(const vector<int> &a) {
  vector<int> b = primitive(derivative(a) * inverse(a));
  b.resize(a.size());
  return b;
}

vector<int> exponent(const vector<int> &a) {
  vector<int> b(1, 1);
  while (b.size() < a.size()) {
    vector<int> c(a.begin(), a.begin() + min(a.size(), b.size() << 1));
    add(c[0], 1);
    vector<int> old_b = b;
    b.resize(b.size() << 1);
    c -= logarithm(b);
    c *= old_b;
    for (int i = b.size() >> 1; i < b.size(); ++i) {
      b[i] = c[i];
    }
  }
  b.resize(a.size());
  return b;
}

vector<int> power(vector<int> a, int m) {
  int n = a.size(), p = -1;
  vector<int> b(n);
  for (int i = 0; i < n; ++i) {
    if (a[i]) {
      p = i;
      break;
    }
  }
  if (p == -1) {
    b[0] = !m;
    return b;
  }
  if ((long long) m * p >= n) {
    return b;
  }
  int mu = power(a[p], m), di = inv(a[p]);
  vector<int> c(n - m * p);
  for (int i = 0; i < n - m * p; ++i) {
    c[i] = mul(a[i + p], di);
  }
  c = logarithm(c);
  for (int i = 0; i < n - m * p; ++i) {
    c[i] = mul(c[i], m);
  }
  c = exponent(c);
  for (int i = 0; i < n - m * p; ++i) {
    b[i + m * p] = mul(c[i], mu);
  }
  return b;
}

vector<int> sqrt(const vector<int> &a) {
  vector<int> b(1, 1);
  while (b.size() < a.size()) {
    vector<int> c(a.begin(), a.begin() + min(a.size(), b.size() << 1));
    vector<int> old_b = b;
    b.resize(b.size() << 1);
    c *= inverse(b);
    for (int i = b.size() >> 1; i < b.size(); ++i) {
      b[i] = mul(c[i], (md + 1) >> 1);
    }
  }
  b.resize(a.size());
  return b;
}

vector<int> multiply_all(int l, int r, vector<vector<int>> &all) {
  if (l > r) {
    return vector<int>();
  } else if (l == r) {
    return all[l];
  } else {
    int y = (l + r) >> 1;
    return multiply_all(l, y, all) * multiply_all(y + 1, r, all);
  }
}

vector<int> evaluate(const vector<int> &f, const vector<int> &x) {
  int n = x.size();
  if (!n) {
    return vector<int>();
  }
  vector<vector<int>> up(n * 2);
  for (int i = 0; i < n; ++i) {
    up[i + n] = vector<int>{(md - x[i]) % md, 1};
  }
  for (int i = n - 1; i; --i) {
    up[i] = up[i << 1] * up[i << 1 | 1];
  }
  vector<vector<int>> down(n * 2);
  down[1] = f % up[1];
  for (int i = 2; i < n * 2; ++i) {
    down[i] = down[i >> 1] % up[i];
  }
  vector<int> y(n);
  for (int i = 0; i < n; ++i) {
    y[i] = down[i + n][0];
  }
  return y;
}

vector<int> interpolate(const vector<int> &x, const vector<int> &y) {
  int n = x.size();
  vector<vector<int>> up(n * 2);
  for (int i = 0; i < n; ++i) {
    up[i + n] = vector<int>{(md - x[i]) % md, 1};
  }
  for (int i = n - 1; i; --i) {
    up[i] = up[i << 1] * up[i << 1 | 1];
  }
  vector<int> a = evaluate(derivative(up[1]), x);
  for (int i = 0; i < n; ++i) {
    a[i] = mul(y[i], inv(a[i]));
  }
  vector<vector<int>> down(n * 2);
  for (int i = 0; i < n; ++i) {
    down[i + n] = vector<int>(1, a[i]);
  }
  for (int i = n - 1; i; --i) {
    down[i] = down[i << 1] * up[i << 1 | 1] + down[i << 1 | 1] * up[i << 1];
  }
  return down[1];
}
posted @ 2022-09-14 23:01  hzy0227  阅读(130)  评论(0编辑  收藏  举报