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BigInt with fft(add,mult,div)___nlogn__10^5 length Number
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BigInt with fft(add,mult,div)___nlogn__10^5 length Number
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typedef long long ll;
typedef long double ld;
typedef complex<ld> pt;
const int MOD = 1e9 + 7;
const ld PI = acos(-1.L);
template<class T> struct cplx {
T x, y; cplx() {x = 0.0; y = 0.0;}
cplx(T nx, T ny=0) {x = nx; y = ny;}
cplx operator+(const cplx &c) const {return {x + c.x, y + c.y};}
cplx operator-(const cplx &c) const {return {x - c.x, y - c.y};}
cplx operator*(const cplx &c) const {return {x*c.x - y*c.y, x*c.y + y*c.x};}
cplx& operator*=(const cplx &c) { return *this={x*c.x-y*c.y, x*c.y+y*c.x}; }
inline T real() const { return x; }
inline T imag() const { return y; }
// Only supports right scalar multiplication like p*c
template<class U> cplx operator*(const U &c) const {return {x*c,y*c};}
template<class U> cplx operator/(const U &c) const {return {x/c,y/c};}
template<class U> void operator/=(const U &c) {x /= c; y /= c;}};
#define polar(r,a) (cplx<ld>){r*cos(a),r*sin(a)}
const int DIG = 9, FDIG = 4;
const int BASE = 1e9, FBASE = 1e4;
typedef cplx<ld> Cplx;
struct BigInt {
int sgn;
vector<int> a;
BigInt() : sgn(1) {}
BigInt(ll v) { *this = v; }
BigInt& operator = (ll v) { sgn = 1; if (v < 0) sgn = -1, v = -v;
a.clear(); for (; v > 0; v /= BASE) a.push_back(v % BASE);
return *this; }
BigInt(const BigInt& other) { sgn = other.sgn; a = other.a; }
friend void swap(BigInt& a, BigInt& b) { swap(a.sgn, b.sgn);
swap(a.a, b.a); }
BigInt& operator = (BigInt other) { swap(*this, other); return *this; }
BigInt(BigInt&& other) : BigInt() { swap(*this, other); }
BigInt(const string& s) { read(s); }
void read(const string& s) {
sgn = 1; a.clear(); int k = 0;
for (; k < s.size() && (s[k] == '-' || s[k] == '+'); k++)
if (s[k] == '-') sgn = -sgn;
for (int i = s.size()-1; i >= k; i -= DIG) {
int x = 0;
for (int j = max(k, i-DIG+1); j <= i; j++) x = x*10 + s[j] - '0';
a.push_back(x); } trim(); }
friend istream& operator>>(istream &in, BigInt &v) {
string s; in >> s; v.read(s); return in; }
friend ostream& operator<<(ostream &out, const BigInt &v) {
if (v.sgn == -1 && !v.zero()) out << '-';
out << (v.a.empty() ? 0 : v.a.back());
for (int i = (int) v.a.size() - 2; i >= 0; --i)
out << setw(DIG) << setfill('0') << v.a[i];
return out; }
bool operator<(const BigInt &v) const { if (sgn != v.sgn) return sgn < v.sgn;
if (a.size() != v.a.size()) return a.size() * sgn < v.a.size() * v.sgn;
for (int i=(int)a.size()-1;i>=0;i--)
if (a[i]!=v.a[i]) return a[i]*sgn < v.a[i]*sgn; return 0; }
bool operator>(const BigInt &v) const { return v < *this; }
bool operator<=(const BigInt &v) const { return !(v < *this); }
bool operator>=(const BigInt &v) const { return !(*this < v); }
bool operator==(const BigInt &v) const { return !(*this < v) && !(v < *this); }
bool operator!=(const BigInt &v) const { return *this < v || v < *this; }
friend int __cmp(const BigInt& x, const BigInt& y) {
if (x.a.size() != y.a.size()) return x.a.size() < y.a.size() ? -1 : 1;
for (int i = (int) x.a.size() - 1; i >= 0; --i) if (x.a[i] != y.a[i])
return x.a[i] < y.a[i] ? -1 : 1; return 0; }
BigInt operator-() const { BigInt res = *this; if (zero()) return res;
res.sgn = -sgn; return res; }
void __add(const BigInt& v) { if (a.size() < v.a.size()) a.resize(v.a.size(), 0);
for (int i = 0, carry = 0; i < max(a.size(), v.a.size()) || carry; ++i) {
if (i == a.size()) a.push_back(0);
a[i] += carry + (i < (int) v.a.size() ? v.a[i] : 0); carry = a[i] >= BASE;
if (carry) a[i] -= BASE; } }
void __sub(const BigInt& v) {
for (int i = 0, carry = 0; i < (int) v.a.size() || carry; ++i) {
a[i] -= carry + (i < (int) v.a.size() ? v.a[i] : 0);
carry = a[i] < 0; if (carry) a[i] += BASE; } this->trim(); }
BigInt operator+=(const BigInt& v) { if (sgn == v.sgn) __add(v);
else if (__cmp(*this, v) >= 0) __sub(v);
else { BigInt vv = v; swap(*this, vv); __sub(vv); } return *this; }
BigInt operator-=(const BigInt& v) { if (sgn == v.sgn) {
if (__cmp(*this, v) >= 0) __sub(v);
else { BigInt vv = v; swap(*this, vv); __sub(vv); sgn = -sgn; } }
else __add(v); return *this; }
template< typename L, typename R >
typename enable_if<
is_convertible<L, BigInt>::value &&
is_convertible<R, BigInt>::value &&
is_lvalue_reference<R&&>::value,
BigInt>::type friend operator + (L&& l, R&& r) {
BigInt result(forward<L>(l));
result += r;
return result;
}
template< typename L, typename R >
typename enable_if<
is_convertible<L, BigInt>::value &&
is_convertible<R, BigInt>::value &&
is_rvalue_reference<R&&>::value,
BigInt>::type friend operator + (L&& l, R&& r) {
BigInt result(move(r));
result += l;
return result;
}
template< typename L, typename R >
typename enable_if<
is_convertible<L, BigInt>::value &&
is_convertible<R, BigInt>::value,
BigInt>::type friend operator - (L&& l, R&& r) {
BigInt result(forward<L>(l));
result -= r;
return result;
}
friend pair<BigInt, BigInt> divmod(const BigInt& a1, const BigInt& b1) {
ll norm = BASE / (b1.a.back()+1); BigInt a = a1.abs()*norm, b = b1.abs()*norm, q = 0, r = 0;
q.a.resize(a.a.size());
for (int i = a.a.size()-1; i >= 0; i--) { r *= BASE; r += a.a[i];
ll s1 = r.a.size() <= b.a.size() ? 0 : r.a[b.a.size()];
ll s2 = r.a.size() <= b.a.size() - 1 ? 0 : r.a[b.a.size() - 1];
ll d = ((ll) BASE * s1 + s2) / b.a.back(); r -= b * d;
while (r < 0) r += b, --d; q.a[i] = d; }
q.sgn = a1.sgn * b1.sgn; r.sgn = a1.sgn; q.trim(); r.trim();
auto res = make_pair(q, r / norm); if (res.second < 0) res.second += b1; return res; }
BigInt operator/(const BigInt &v) const { return divmod(*this, v).first; }
BigInt operator%(const BigInt &v) const { return divmod(*this, v).second; }
void operator/=(int v) { if (llabs(v) >= BASE) { *this /= BigInt(v); return; }
if (v < 0) sgn = -sgn, v = -v;
for (int i = (int) a.size()-1, rem = 0; i >= 0; --i) {
ll cur = a[i] + rem * (ll)BASE; a[i] = (int) (cur/v); rem = (int) (cur%v); } trim(); }
BigInt operator/(int v) const { if (llabs(v) >= BASE) return *this / BigInt(v);
BigInt res = *this; res /= v; return res; }
void operator/=(const BigInt &v) { *this = *this / v; }
ll operator%(ll v) const { assert(v < BASE); int m = 0;
for (int i = a.size() - 1; i >= 0; --i) m = (a[i] + m * (ll) BASE) % v;
return m * sgn; }
void operator*=(int v) {
if (llabs(v) >= BASE) { *this *= BigInt(v); return; }
if (v < 0) sgn = -sgn, v = -v;
for (int i = 0, carry = 0; i < a.size() || carry; ++i) {
if (i == a.size()) a.push_back(0);
ll cur = a[i] * (ll) v + carry;
carry = (int) (cur/BASE); a[i] = (int) (cur%BASE); } trim(); }
BigInt operator*(int v) const { if (llabs(v) >= BASE) return *this * BigInt(v);
BigInt res = *this; res *= v; return res; }
static vector<int> convert_base(const vector<int> &a, int old_digits, int new_digits) {
vector<ll> p(max(old_digits, new_digits) + 1);
p[0] = 1;
for (int i = 1; i < (int) p.size(); i++)
p[i] = p[i - 1] * 10;
vector<int> res;
ll cur = 0;
int cur_digits = 0;
for (int i = 0; i < (int) a.size(); i++) {
cur += a[i] * p[cur_digits];
cur_digits += old_digits;
while (cur_digits >= new_digits) {
res.push_back((ll)(cur % p[new_digits]));
cur /= p[new_digits];
cur_digits -= new_digits;
}
}
res.push_back((int) cur);
while (!res.empty() && !res.back())
res.pop_back();
return res;
}
void fft(vector<Cplx>& a, bool invert) const { int n = a.size();
for (int i = 1, j = 0; i < n; ++i) { int bit = n/2;
for (; j >= bit; bit /= 2) j -= bit; j += bit;
if (i < j) swap(a[i], a[j]); }
for (int len = 2; len <= n; len *= 2) {
ld ang = 2 * PI / len * (invert ? -1 : 1);
Cplx wlen = polar(1, ang);
for (int i = 0; i < n; i += len) { Cplx w(1);
for (int j = 0; j < len / 2; ++j) {
Cplx u = a[i + j], v = a[i + j + len / 2] * w;
a[i + j] = u + v; a[i + j + len / 2] = u - v; w *= wlen; } } }
if (invert) for (int i = 0; i < n; ++i) a[i] /= n; }
void multiply_fft(const vector<int> &a, const vector<int> &b, vector<int> &res) const {
vector<Cplx> fa(a.begin(), a.end()), fb(b.begin(), b.end());
int n = 1; while (n < max(a.size(), b.size())) n *= 2; n *= 2; fa.resize(n); fb.resize(n);
fft(fa, 0); fft(fb, 0); for (int i = 0; i < n; ++i) fa[i] *= fb[i]; fft(fa, 1);
res.resize(n); ll carry = 0;
for (int i=0; i<n; i++) { ll t = (ll)(fa[i].real()+0.5)+carry; carry = t/FBASE; res[i] = t%FBASE; } }
static inline int rev_incr(int a, int n) { int msk = n/2, cnt=0;
while ( a&msk ) { cnt++; a<<=1; }
a &= msk-1; a |= msk;
while ( cnt-- ) a >>= 1;
return a; }
static vector<Cplx> FFT(vector<Cplx> v, int dir=1) {
Cplx wm,w,u,t; int n = v.size(); vector<Cplx> V(n);
for (int k=0,a=0; k<n; ++k, a=rev_incr(a,n))
V[a] = v[k] / ld(dir>0 ? 1 : n);
for (int m=2; m<=n; m<<=1) {
wm = polar( (ld)1, dir*2*PI/m );
for (int k=0; k<n; k+=m) {
w = 1;
for (int j=0; j<m/2; ++j, w*=wm) {
u = V[k + j];
t = w * V[k + j + m/2];
V[k + j] = u + t;
V[k + j + m/2] = u - t;
} } } return V; }
static void convolution(const vector<int>& a, const vector<int>& b, vector<int>& c) {
int sz = a.size()+b.size()-1;
int n = 1<<int(ceil(log2(sz)));
vector<Cplx> av(n,0), bv(n,0), cv;
for (int i=0; i<a.size(); i++) av[i] = a[i];
for (int i=0; i<b.size(); i++) bv[i] = b[i];
cv = FFT(bv); bv = FFT(av);
for (int i=0; i<n; i++) av[i] = bv[i]*cv[i];
cv = FFT(av, -1);
c.resize(n); ll carry = 0;
for (int i=0; i<n; i++) { ll t = ll(cv[i].real()+0.5)+carry; carry = t/FBASE; c[i] = t%FBASE; } }
BigInt mul_simple(const BigInt &v) const { BigInt res; res.sgn = sgn * v.sgn;
res.a.resize(a.size() + v.a.size());
for (int i=0; i<a.size(); i++) if (a[i])
for (int j=0, carry=0; j<v.a.size() || carry; j++) {
ll cur = res.a[i + j] + (ll) a[i] * (j < v.a.size() ? v.a[j] : 0) + carry;
carry = (int) (cur / BASE); res.a[i + j] = (int) (cur % BASE); } res.trim(); return res; }
BigInt mul_fft(const BigInt& v) const { BigInt res;
convolution(convert_base(a, DIG, FDIG), convert_base(v.a, DIG, FDIG), res.a);
res.a = convert_base(res.a, FDIG, DIG); res.trim(); return res; }
void operator*=(const BigInt &v) { *this = *this * v; }
BigInt operator*(const BigInt &v) const {
if (a.size() * v.a.size() <= 100111) return mul_simple(v); return mul_fft(v); }
BigInt abs() const { BigInt res = *this; res.sgn *= res.sgn; return res; }
void trim() { while (!a.empty() && !a.back()) a.pop_back(); }
bool zero() const { return a.empty() || (a.size() == 1 && !a[0]); }
friend BigInt gcd(const BigInt &a, const BigInt &b) { return b.zero() ? a : gcd(b, a % b); }
};