bigint_dec.h

// filename:    bigint_dec.h
// author:      baobaobear
// create date: 2021-02-08
// This library is compatible with C++03
// https://github.com/Baobaobear/MiniBigInteger
#pragma once
#include "bigint_base.h"

//{dec_b}{decm_b}
namespace BigIntDecNS {
#if BIGINT_LARGE_BASE
const int32_t COMPRESS_MOD = 100000000;
const uint32_t COMPRESS_DIGITS = 8;
const int32_t COMPRESS_HALF_MOD = 10000;
const uint32_t COMPRESS_HALF_DIGITS = 4;
#else
const int32_t COMPRESS_MOD = 10000;
const uint32_t COMPRESS_DIGITS = 4;
#endif

const uint32_t BIGINT_NTT_THRESHOLD = BIGINT_X64 ? 1700 : 1300;
const uint32_t BIGINT_MUL_THRESHOLD = 90;
const uint32_t BIGINT_DIV_THRESHOLD = 1500;
const uint32_t BIGINT_DIVIDEDIV_THRESHOLD = BIGINT_MUL_THRESHOLD * 3;
#if BIGINT_X64
const uint32_t NTT_MAX_SIZE = 1 << 24;
#else
const uint32_t NTT_MAX_SIZE = 1 << 21;
#endif

template <typename T> inline T high_digit(T digit) { return digit / (T)COMPRESS_MOD; }

template <typename T> inline uint32_t low_digit(T digit) { return (uint32_t)(digit % (T)COMPRESS_MOD); }

class BigIntDec {
protected:
    typedef uint32_t base_t;
#if BIGINT_LARGE_BASE
    typedef int64_t carry_t;
    typedef uint64_t ucarry_t;
#else
    typedef int32_t carry_t;
    typedef uint32_t ucarry_t;
#endif
    int sign;
    std::vector<base_t> v;
    typedef BigIntDec BigInt_t;
    template <typename _Tx, typename _Ty> static inline void carry(_Tx &add, _Ty &baseval, _Tx newval) {
        add += newval;
        baseval = low_digit(add);
        add = high_digit(add);
    }
    template <typename _Tx, typename _Ty> static inline void borrow(_Tx &add, _Ty &baseval, _Tx newval) {
        add += newval - COMPRESS_MOD + 1;
        baseval = (_Tx)low_digit(add) + COMPRESS_MOD - 1;
        add = high_digit(add);
    }

    bool raw_less(const BigInt_t &b) const {
        if (v.size() != b.size()) return v.size() < b.size();
        for (size_t i = v.size() - 1; i < v.size(); i--)
            if (v[i] != b.v[i]) return v[i] < b.v[i];
        return false; // eq
    }
    bool raw_eq(const BigInt_t &b) const {
        if (this == &b) return true;
        if (v.size() != b.size()) return false;
        for (size_t i = 0; i < v.size(); ++i)
            if (v[i] != b.v[i]) return false;
        return true;
    }
    BigInt_t &raw_add(const BigInt_t &b) {
        if (v.size() < b.size()) v.resize(b.size());
        ucarry_t add = 0;
        for (size_t i = 0; i < b.v.size(); i++)
            carry(add, v[i], (ucarry_t)(v[i] + b.v[i]));
        for (size_t i = b.v.size(); add && i < v.size(); i++)
            carry(add, v[i], (ucarry_t)v[i]);
        add ? v.push_back((base_t)add) : trim();
        return *this;
    }
    BigInt_t &raw_offset_add(const BigInt_t &b, size_t offset) {
        ucarry_t add = 0;
        for (size_t i = 0; i < b.size(); ++i)
            carry(add, v[i + offset], (ucarry_t)(v[i + offset] + b.v[i]));
        for (size_t i = b.size() + offset; add; ++i)
            carry(add, v[i], (ucarry_t)v[i]);
        return *this;
    }
    BigInt_t &raw_sub(const BigInt_t &b) {
        if (v.size() < b.v.size()) v.resize(b.v.size());
        carry_t add = 0;
        for (size_t i = 0; i < b.v.size(); i++)
            borrow(add, v[i], (carry_t)v[i] - (carry_t)b.v[i]);
        for (size_t i = b.v.size(); add && i < v.size(); i++)
            borrow(add, v[i], (carry_t)v[i]);
        if (add) {
            sign = -sign;
            add = 1;
            for (size_t i = 0; i < v.size(); i++)
                carry(add, v[i], (carry_t)(COMPRESS_MOD - v[i] - 1));
        }
        trim();
        return *this;
    }
    BigInt_t &raw_offset_mulsub(const BigInt_t &b, base_t mul, size_t offset) {
        if (mul == 0) return *this;
        carry_t add = 0;
        for (size_t i = 0; i < b.v.size(); i++)
            borrow(add, v[i + offset], (carry_t)v[i + offset] - (carry_t)b.v[i] * (carry_t)mul);
        for (size_t i = offset + b.v.size(); add && i < v.size(); i++)
            borrow(add, v[i], (carry_t)v[i]);
        return *this;
    }
    BigInt_t &raw_mul_int(base_t m) {
        if (m == 0) {
            set(0);
            return *this;
        } else if (m == 1)
            return *this;
        ucarry_t add = 0;
        size_t i = 0;
        for (; i + 4 <= v.size(); i += 4) {
            carry(add, v[i], v[i] * (ucarry_t)m);
            carry(add, v[i + 1], v[i + 1] * (ucarry_t)m);
            carry(add, v[i + 2], v[i + 2] * (ucarry_t)m);
            carry(add, v[i + 3], v[i + 3] * (ucarry_t)m);
            // carry(add, v[i + 4], v[i + 4] * (ucarry_t)m);
            // carry(add, v[i + 5], v[i + 5] * (ucarry_t)m);
            // carry(add, v[i + 6], v[i + 6] * (ucarry_t)m);
            // carry(add, v[i + 7], v[i + 7] * (ucarry_t)m);
        }
        for (; i < v.size(); i++)
            carry(add, v[i], v[i] * (ucarry_t)m);
        if (add) v.push_back((base_t)add);
        return *this;
    }
    BigInt_t &raw_mul(const BigInt_t &a, const BigInt_t &b) {
        if (a.is_zero() || b.is_zero()) {
            return set(0);
        }
        if (a.size() == 1 && a.v[0] == 1) {
            *this = b;
            sign *= a.sign;
            return *this;
        }
        if (b.size() == 1 && b.v[0] == 1) {
            *this = a;
            sign *= b.sign;
            return *this;
        }
        if (a.size() == 2 && a.v[1] == 1 && a.v[0] == 0) {
            *this = b;
            raw_shl(1);
            sign *= a.sign;
            return *this;
        }
        if (b.size() == 2 && b.v[1] == 1 && b.v[0] == 0) {
            *this = a;
            raw_shl(1);
            sign *= b.sign;
            return *this;
        }
        v.clear();
        v.resize(a.size() + b.size());
        for (size_t i = 0; i < a.size(); i++) {
            ucarry_t add = 0, av = a.v[i];
            size_t j = 0;
            for (; j + 4 <= b.size(); j += 4) {
                carry(add, v[i + j], v[i + j] + av * b.v[j]);
                carry(add, v[i + j + 1], v[i + j + 1] + av * b.v[j + 1]);
                carry(add, v[i + j + 2], v[i + j + 2] + av * b.v[j + 2]);
                carry(add, v[i + j + 3], v[i + j + 3] + av * b.v[j + 3]);
                // carry(add, v[i + j + 4], v[i + j + 4] + av * b.v[j + 4]);
                // carry(add, v[i + j + 5], v[i + j + 5] + av * b.v[j + 5]);
                // carry(add, v[i + j + 6], v[i + j + 6] + av * b.v[j + 6]);
                // carry(add, v[i + j + 7], v[i + j + 7] + av * b.v[j + 7]);
            }
            for (; j < b.size(); ++j) {
                carry(add, v[i + j], v[i + j] + av * b.v[j]);
            }
            v[i + b.size()] += (base_t)add;
        }
        trim();
        return *this;
    }
    // Karatsuba algorithm
    BigInt_t &raw_mul_karatsuba(const BigInt_t &a, const BigInt_t &b) {
        if (std::min(a.size(), b.size()) <= BIGINT_MUL_THRESHOLD) {
            return raw_mul(a, b);
        }
        if (a.size() * 2 < b.size() || b.size() * 2 < a.size()) { // split
            BigInt_t t;
            if (a.size() < b.size()) {
                size_t split = b.size() / 2;
                t.raw_mul_karatsuba(a, b.raw_shr_to(split));
                t.raw_shl(split);
                raw_mul_karatsuba(a, b.raw_lowdigits_to(split));
                raw_add(t);
            } else {
                size_t split = a.size() / 2;
                t.raw_mul_karatsuba(b, a.raw_shr_to(split));
                t.raw_shl(split);
                raw_mul_karatsuba(b, a.raw_lowdigits_to(split));
                raw_add(t);
            }
            return *this;
        }
        if (std::min(a.size(), b.size()) <= BIGINT_NTT_THRESHOLD)
            ;
        else if ((a.size() + b.size()) <= NTT_MAX_SIZE)
            return raw_nttmul(a, b);
        BigInt_t ah, al, bh, bl, h, m;
        size_t split = std::max(std::min((a.size() + 1) / 2, b.size() - 1), std::min(a.size() - 1, (b.size() + 1) / 2));
        al.v.assign(a.v.begin(), a.v.begin() + split);
        ah.v.assign(a.v.begin() + split, a.v.end());
        bl.v.assign(b.v.begin(), b.v.begin() + split);
        bh.v.assign(b.v.begin() + split, b.v.end());

        raw_mul_karatsuba(al, bl);
        h.raw_mul_karatsuba(ah, bh);
        m.raw_mul_karatsuba(al + ah, bl + bh);
        m.raw_sub(*this);
        m.raw_sub(h);
        v.resize(a.size() + b.size());

        raw_offset_add(m, split);
        raw_offset_add(h, split * 2);
        trim();
        return *this;
    }
    BigInt_t &raw_nttmul(const BigInt_t &a, const BigInt_t &b) {
        if (std::min(a.size(), b.size()) <= BIGINT_MUL_THRESHOLD) {
            return raw_mul(a, b);
        }
        if (std::min(a.size(), b.size()) <= BIGINT_NTT_THRESHOLD || (a.size() + b.size()) > NTT_MAX_SIZE) {
            return raw_mul_karatsuba(a, b);
        }
        if (a.size() * 3 < b.size() || b.size() * 3 < a.size()) { // split
            BigInt_t t;
            if (a.size() < b.size()) {
                size_t split = b.size() / 2;
                t.raw_nttmul(a, b.raw_shr_to(split));
                t.raw_shl(split);
                raw_nttmul(a, b.raw_lowdigits_to(split));
                raw_add(t);
            } else {
                size_t split = a.size() / 2;
                t.raw_nttmul(b, a.raw_shr_to(split));
                t.raw_shl(split);
                raw_nttmul(b, a.raw_lowdigits_to(split));
                raw_add(t);
            }
            return *this;
        }
        size_t len;
        std::vector<NTT_NS::ntt_base_t> &ntt_a = NTT_NS::ntt1.ntt_a, &ntt_b = NTT_NS::ntt1.ntt_b;
        std::vector<int64_t> &ntt_c = NTT_NS::ntt1.ntt_c;
#if BIGINT_LARGE_BASE
        ntt_a.resize(a.size() * 2);
        ntt_b.resize(b.size() * 2);
        for (size_t i = 0, j = 0; i < a.size(); ++i, ++j) {
            ntt_a[j] = a.v[i] % COMPRESS_HALF_MOD;
            ntt_a[++j] = a.v[i] / COMPRESS_HALF_MOD;
        }
        if (a == b) {
            NTT_NS::ntt_prepare(a.size() * 2, a.size() * 2, len, 7);
            NTT_NS::sqr_conv();
            len = a.size() * 4;
        } else {
            for (size_t i = 0, j = 0; i < b.size(); ++i, ++j) {
                ntt_b[j] = b.v[i] % COMPRESS_HALF_MOD;
                ntt_b[++j] = b.v[i] / COMPRESS_HALF_MOD;
            }
            NTT_NS::ntt_prepare(a.size() * 2, b.size() * 2, len, 7);
            NTT_NS::mul_conv();
            len = (a.size() + b.size()) * 2;
        }
#else
        ntt_a.resize(a.size());
        ntt_b.resize(b.size());
        for (size_t i = 0; i < a.size(); ++i) {
            ntt_a[i] = a.v[i];
        }
        if (a == b) {
            NTT_NS::ntt_prepare(a.size(), a.size(), len, 7);
            NTT_NS::sqr_conv();
            len = a.size() * 2;
        } else {
            for (size_t i = 0; i < b.size(); ++i) {
                ntt_b[i] = b.v[i];
            }
            NTT_NS::ntt_prepare(a.size(), b.size(), len, 7);
            NTT_NS::mul_conv();
            len = a.size() + b.size();
        }
#endif
        while (len > 0 && ntt_c[--len] == 0)
            ;
        v.clear();
        uint64_t add = 0;
#if BIGINT_LARGE_BASE
        v.reserve(++len / 2 + 2);
        for (size_t i = 0; i < len; i += 2) {
            add += ntt_c[i] + (ntt_c[i + 1] * COMPRESS_HALF_MOD);
            v.push_back(low_digit(add));
            add = high_digit(add);
        }
#else
        v.reserve(len + 3);
        for (size_t i = 0; i <= len; i++) {
            add += ntt_c[i];
            v.push_back(low_digit(add));
            add = high_digit(add);
        }
#endif
        for (; add; add = high_digit(add))
            v.push_back(low_digit(add));
        trim();
        return *this;
    }
    BigInt_t &raw_div(const BigInt_t &a, const BigInt_t &b, BigInt_t &r) {
        r = a;
        if (a.raw_less(b)) {
            return set(0);
        } else if (b.size() == 2 && b.v[1] == 1 && b.v[0] == 0) {
            *this = a;
            r.set(a.v[0]);
            return raw_shr(1);
        }
        v.clear();
        v.resize(a.size() - b.size() + 1);
        r.v.resize(a.size() + 1);
        size_t offset = b.size();
        double db = b.v.back();
#if BIGINT_LARGE_BASE
        if (b.size() > 2) {
            double t = b.v[b.size() - 2] + b.v[b.size() - 3] / (double)COMPRESS_MOD;
            db += (b.v.back() / (double)COMPRESS_HALF_MOD + t) / COMPRESS_MOD;
        } else if (b.size() > 1) {
            db += (b.v.back() / (double)COMPRESS_HALF_MOD + b.v[b.size() - 2]) / COMPRESS_MOD;
        }
#else
        if (b.size() > 2) {
            db += (b.v[b.size() - 2] + (b.v[b.size() - 3] + 1) / (double)COMPRESS_MOD) / COMPRESS_MOD;
        } else if (b.size() > 1) {
            db += b.v[b.size() - 2] / (double)COMPRESS_MOD;
        }
#endif
        db = 1 / db;
        for (size_t i = a.size() - offset, j = a.size() - 1; i <= a.size();) {
            carry_t rm = (carry_t)r.v[j + 1] * COMPRESS_MOD + r.v[j], m;
            m = std::max((carry_t)(rm * db), (carry_t)r.v[i + offset]);
            v[i] += (base_t)m;
            r.raw_offset_mulsub(b, (base_t)m, i);
            if (!r.v[j + 1]) --i, --j;
        }
        r.trim();
        carry_t add = 0;
        while (!r.raw_less(b)) {
            r.raw_sub(b);
            ++add;
        }

        for (size_t i = 0; i < v.size(); i++)
            carry(add, v[i], (carry_t)v[i]);
        trim();
        return *this;
    }
    BigInt_t &raw_shr(size_t n) {
        if (n == 0) return *this;
        if (n >= size()) {
            set(0);
            return *this;
        }
        v.erase(v.begin(), v.begin() + n);
        return *this;
    }
    BigInt_t raw_shr_to(size_t n) const {
        BigInt_t r;
        if (n >= size()) return r;
        r.v.assign(v.begin() + n, v.end());
        return BIGINT_STD_MOVE(r);
    }
    BigInt_t raw_lowdigits_to(size_t n) const {
        if (n >= size()) return *this;
        BigInt_t r;
        r.v.assign(v.begin(), v.begin() + n);
        r.trim();
        return BIGINT_STD_MOVE(r);
    }
    BigInt_t &raw_shl(size_t n) {
        if (n == 0 || is_zero()) return *this;
        v.insert(v.begin(), n, 0);
        return *this;
    }
    BigInt_t &keep(size_t n) {
        size_t s = n < v.size() ? v.size() - n : (size_t)0;
        if (s && v[s - 1] >= COMPRESS_MOD >> 1) ++v[s];
        return raw_shr(s);
    }
    BigInt_t &raw_fastdiv(const BigInt_t &a, const BigInt_t &b) {
        if (a.raw_less(b)) {
            set(0);
            return *this;
        }
        if (b.size() * 2 - 2 > a.size()) {
            BigInt_t ta = a, tb = b;
            size_t ans_len = a.size() - b.size() + 2;
            size_t r = b.size() - ans_len;
            ta.raw_shr(r);
            tb.raw_shr(r);
            return raw_fastdiv(ta, tb);
        }
        if (b.size() < BIGINT_DIV_THRESHOLD) {
            BigInt_t r;
            return raw_div(a, b, r);
        }
        size_t extand_digs = 2;
        size_t ans_len = a.size() - b.size() + extand_digs + 1, s_len = ans_len + 32;
        std::vector<size_t> len_seq;
        BigInt_t b2, x0, x1, t;
        x1.v.resize(1);
        x1.v.back() = (base_t)(COMPRESS_MOD / (b.v.back() + (double)(b.v[b.size() - 2]) / COMPRESS_MOD));
        x0.v.push_back(x1.v.back() + 1);
        size_t keep_size = 1;
        while (s_len > 32) {
            len_seq.push_back(std::min(s_len, ans_len));
            s_len = s_len / 2 + 1;
        }
        while (x1 != x0) {
            // x1 = x0(2 - x0 * b)
            x0 = x1;
            b2 = b;
            size_t tsize = std::min(keep_size * 2, ans_len);
            b2.keep(tsize);
            t = x0 * b2;
            t.keep(tsize);
            for (size_t i = t.size() - 2; i < t.size(); --i)
                t.v[i] = COMPRESS_MOD - 1 - t.v[i];
            if (t.v.back() != 1) {
                t.v.back() = COMPRESS_MOD - 1 - t.v.back();
                t.v.push_back(1);
            } else {
                t.v.pop_back();
                t.trim();
            }
            x1 *= t;
            keep_size = std::min(keep_size * 2, s_len);
            x1.keep(keep_size);
        }
        for (; !len_seq.empty(); len_seq.pop_back()) {
            // x1 = x0(2 - x0 * b)
            x0 = x1;
            b2 = b;
            size_t tsize = std::min(keep_size * 2, ans_len);
            b2.keep(tsize);
            t = x0 * b2;
            t.keep(tsize);
            for (size_t i = t.size() - 2; i < t.size(); --i)
                t.v[i] = COMPRESS_MOD - 1 - t.v[i];
            if (t.v.back() != 1) {
                t.v.back() = COMPRESS_MOD - 1 - t.v.back();
                t.v.push_back(1);
            } else {
                t.v.pop_back();
                t.trim();
            }
            ucarry_t add = 1;
            for (size_t i = 0; add && i < t.v.size(); i++)
                carry(add, t.v[i], (ucarry_t)t.v[i]);
            if (add) t.v.push_back((base_t)add);
            x1 *= t;
            keep_size = len_seq.back();
            x1.keep(keep_size);
        }
        x1 *= a;
        if (x1.v[a.size() + extand_digs - 1] >= COMPRESS_MOD - 1)
            *this = x1.raw_shr(a.size() + extand_digs).raw_add(BigInt_t(1));
        else
            *this = x1.raw_shr(a.size() + extand_digs);
        return *this;
    }
    BigInt_t &raw_dividediv_recursion(const BigInt_t &a, const BigInt_t &b, BigInt_t &r) {
        if (a < b) {
            r = a;
            return set(0);
        } else if (b.size() <= BIGINT_DIVIDEDIV_THRESHOLD) {
            return raw_div(a, b, r);
        }
        size_t base = (b.size() + 1) / 2;
        if (a.size() <= base * 3) {
            base = b.size() / 2;
            BigInt_t ma = a, mb = b, e;
            BigInt_t ha = ma.raw_shr_to(base);
            BigInt_t hb = mb.raw_shr_to(base);
            raw_dividediv_recursion(ha, hb, r);
            ha = *this * b;
            while (a < ha) {
                ha.raw_sub(b);
                raw_sub(BigInt_t(1));
            }
            r = a - ha;
            return *this;
        }
        if (a.size() > base * 4) base = a.size() / 2;
        BigInt_t ha = a.raw_shr_to(base);
        BigInt_t c, d, m;
        raw_dividediv_recursion(ha, b, d);
        raw_shl(base);
        m.v.resize(base + d.size());
        for (size_t i = 0; i < base; ++i)
            m.v[i] = a.v[i];
        for (size_t i = 0; i < d.size(); ++i)
            m.v[base + i] = d.v[i];
        c.raw_dividediv_recursion(m, b, r);
        raw_add(c);
        return *this;
    }
    BigInt_t &raw_dividediv(const BigInt_t &a, const BigInt_t &b, BigInt_t &r) {
        if (b.size() <= BIGINT_DIVIDEDIV_THRESHOLD) {
            raw_div(a, b, r);
            return *this;
        }
        if (b.size() * 2 - 2 > a.size()) {
            BigInt_t ta = a, tb = b;
            size_t ans_len = a.size() - b.size() + 2;
            size_t shr = b.size() - ans_len;
            ta.raw_shr(shr);
            tb.raw_shr(shr);
            return raw_dividediv(ta, tb, r);
        }
        carry_t mul = (carry_t)(((uint64_t)(COMPRESS_MOD + 1) * (COMPRESS_MOD - 1)) /       //
                                (*(b.v.begin() + b.v.size() - 1) * (uint64_t)COMPRESS_MOD + //
                                 *(b.v.begin() + b.v.size() - 2) + 1));
        BigInt_t ma = a * BigInt_t((intmax_t)mul), mb = b * BigInt_t((intmax_t)mul);
        while (mb.v.back() < COMPRESS_MOD >> 1) {
            int32_t m = 2;
            ma.raw_mul_int(m);
            mb.raw_mul_int(m);
            mul *= m;
        }
        BigInt_t d;
        ma.sign = mb.sign = 1;
        raw_dividediv_recursion(ma, mb, d);
        r.raw_div(d, BigInt_t((int)mul), ma);
        return *this;
    }
    void trim() {
        while (v.back() == 0 && v.size() > 1)
            v.pop_back();
    }
    size_t size() const { return v.size(); }
    //{decm_e}
    BigIntBase transbase(int32_t out_base) const {
        if (size() <= 8) {
            BigIntBase sum(out_base);
            BigIntBase base(out_base);
            BigIntBase ownbase(out_base);
            ownbase.set(COMPRESS_MOD);
            {
                base.set(1);
                BigIntBase mul(out_base);
                mul = base;
                mul.raw_mul_int(v[0]);
                sum.raw_add(mul);
            }
            for (size_t i = 1; i < v.size(); i++) {
                base.raw_mul(ownbase, BigIntBase(base));
                BigIntBase mul(out_base);
                mul = base;
                mul.raw_mul_int(v[i]);
                sum.raw_add(mul);
            }
            return BIGINT_STD_MOVE(sum);
        } else {
            static std::vector<BigIntBase> pow_list;
            static int32_t last_base = 0, pow_list_cnt;
            BigIntBase base(out_base);
            if (out_base != last_base) {
                pow_list.clear();
                pow_list.push_back(base.set(COMPRESS_MOD));
                pow_list_cnt = 0;
                last_base = out_base;
            }
            size_t s = 1, id = 0;
            for (; s < size() / 3; s *= 2, ++id) {
                if (s >= (size_t)1 << pow_list_cnt) {
                    pow_list.push_back(BigIntBase(out_base));
                    pow_list.back().raw_nttsqr(pow_list[pow_list_cnt]);
                    ++pow_list_cnt;
                }
            }
            base = pow_list[id];
            BigInt_t h = raw_shr_to(s), l = *this;
            l.v.resize(s);
            BigIntBase r = h.transbase(out_base);
            BigIntBase sum(out_base);
            sum.raw_nttmul(r, base);
            r = l.transbase(out_base);
            sum.raw_add(r);
            return BIGINT_STD_MOVE(sum);
        }
    }
    std::string out_mul(int32_t out_base = 10, int32_t pack = 0) const {
        BigIntBase sum = transbase(out_base);
        std::string out;
        int32_t d = 0;
        for (size_t i = 0, j = 0;;) {
            if (j < 1) {
                if (i < sum.size())
                    d += sum.v[i];
                else if (d == 0)
                    break;
                j += sum.digits;
                ++i;
            }
            if (out_base <= 10 || d % out_base < 10) {
                out.push_back(char((d % out_base) + '0'));
            } else {
                out.push_back(char((d % out_base) + 'A' - 10));
            }
            d /= out_base;
            j -= 1;
        }
        if (pack == 0)
            while (out.size() > 1 && *out.rbegin() == '0')
                out.erase(out.begin() + out.size() - 1);
        else
            while ((int32_t)out.size() > pack && *out.rbegin() == '0')
                out.erase(out.begin() + out.size() - 1);
        while ((int32_t)out.size() < pack)
            out.push_back('0');
        if (out.empty()) out.push_back('0');
        if (sign < 0 && !this->is_zero()) out.push_back('-');
        std::reverse(out.begin(), out.end());
        return out;
    }
    //{decm_b}
    std::string out_dec() const {
        if (is_zero()) return "0";
        std::string out;
        int32_t d = 0;
        for (size_t i = 0, j = 0;;) {
            if (j < 1) {
                if (i < size())
                    d += v[i];
                else if (d == 0)
                    break;
                j += COMPRESS_DIGITS;
                ++i;
            }
            out.push_back((d % 10) + '0');
            d /= 10;
            j -= 1;
        }
        while (out.size() > 1 && *out.rbegin() == '0')
            out.erase(out.begin() + out.size() - 1);
        if (sign < 0 && !this->is_zero()) out.push_back('-');
        std::reverse(out.begin(), out.end());
        return out;
    }
    BigInt_t &from_str_base10(const char *s) {
        v.clear();
        int32_t base = 10, sign = 1, digits = COMPRESS_DIGITS;
        const char *p = s + strlen(s) - 1;
        while (*s == '-')
            sign *= -1, ++s;
        while (*s == '0')
            ++s;

        int64_t d = digits, hdigit = 0, hdigit_mul = 1;
        for (; p >= s; p--) {
            hdigit += (*p - '0') * hdigit_mul;
            hdigit_mul *= base;
            if (--d == 0) {
                v.push_back((base_t)hdigit);
                d = digits;
                hdigit = 0;
                hdigit_mul = 1;
            }
        }
        if (hdigit || v.empty()) {
            v.push_back((base_t)hdigit);
        }
        this->sign = sign;
        return *this;
    }
    //{decm_e}
    BigInt_t &_from_str(const std::string &s, int base) {
        if (s.size() <= 12) {
            int64_t v = 0;
            for (size_t i = 0; i < s.size(); ++i) {
                int digit = -1;
                if (s[i] >= '0' && s[i] <= '9')
                    digit = s[i] - '0';
                else if (s[i] >= 'A' && s[i] <= 'Z')
                    digit = s[i] - 'A' + 10;
                else if (s[i] >= 'a' && s[i] <= 'z')
                    digit = s[i] - 'a' + 10;
                v = v * base + digit;
            }
            return set(v);
        }
        BigInt_t m(base), h;
        size_t len = 1;
        for (; len * 3 < s.size(); len *= 2) {
            m *= m;
        }
        h._from_str(s.substr(0, s.size() - len), base);
        _from_str(s.substr(s.size() - len), base);
        *this += m * h;
        return *this;
    }
    //{decm_b}
public:
    BigIntDec() { set(0); }
    explicit BigIntDec(int n) { set(n); }
    explicit BigIntDec(intmax_t n) { set(n); }
    explicit BigIntDec(const char *s, int base = 10) { from_str(s, base); }
    explicit BigIntDec(const std::string &s, int base = 10) { from_str(s, base); }
    BigInt_t &set(intmax_t n) {
        v.resize(1);
        v[0] = 0;
        uintmax_t s;
        if (n < 0) {
            sign = -1;
            s = -n;
        } else {
            sign = 1;
            s = n;
        }
        for (size_t i = 0; s; i++) {
            v.resize(i + 1);
            v[i] = low_digit(s);
            s = high_digit(s);
        }
        return *this;
    }
    BigInt_t &from_str(const char *s, int base = 10) {
        //{decm_e}
        if (base == 10) {
            //{decm_b}
            return from_str_base10(s);
            //{decm_e}
        }
        int vsign = 1, i = 0;
        while (s[i] == '-') {
            ++i;
            vsign = -vsign;
        }
        _from_str(std::string(s + i), base);
        sign = vsign;
        return *this;
        //{decm_b}
    }
    BigInt_t &from_str(const std::string &s, int base = 10) { return this->from_str(s.c_str(), base); }
    bool is_zero() const {
        if (v.size() == 1 && v[0] == 0) return true;
        return false;
    }
    bool operator<(const BigInt_t &b) const {
        if (sign * b.sign > 0) {
            if (sign > 0)
                return raw_less(b);
            else
                return b.raw_less(*this);
        } else {
            if (sign > 0)
                return false;
            else
                return true;
        }
    }
    bool operator==(const BigInt_t &b) const {
        if (is_zero() && b.is_zero()) return true;
        if (sign != b.sign) return false;
        return raw_eq(b);
    }
    LESS_THAN_AND_EQUAL_COMPARABLE(BigInt_t)

    BigInt_t &operator=(intmax_t n) { return set(n); }
    BigInt_t &operator=(const char *s) { return from_str(s); }
    BigInt_t &operator=(const std::string s) { return from_str(s); }
    BigInt_t operator+(const BigInt_t &b) const {
        if (sign * b.sign > 0)
            return BIGINT_STD_MOVE(BigInt_t(*this).raw_add(b));
        else if (size() < b.size())
            return BIGINT_STD_MOVE(BigInt_t(b).raw_sub(*this).inv());
        else
            return BIGINT_STD_MOVE(BigInt_t(*this).raw_sub(b));
    }
    BigInt_t &operator+=(const BigInt_t &b) {
        if (this == &b)
            return *this += BigInt_t(b);
        if (sign * b.sign > 0)
            raw_add(b);
        else if (size() < b.size())
            *this = BIGINT_STD_MOVE(BigInt_t(b).raw_sub(*this).inv());
        else
            raw_sub(b);
        return *this;
    }

    BigInt_t operator-(const BigInt_t &b) const {
        if (sign * b.sign < 0)
            return BIGINT_STD_MOVE(BigInt_t(*this).raw_add(b));
        else if (size() < b.size())
            return BIGINT_STD_MOVE(BigInt_t(b).raw_sub(*this).inv());
        else
            return BIGINT_STD_MOVE(BigInt_t(*this).raw_sub(b));
    }
    BigInt_t &operator-=(const BigInt_t &b) {
        if (this == &b) {
            set(0);
            return *this;
        }
        if (sign * b.sign < 0)
            raw_add(b);
        else if (size() < b.size())
            *this = BIGINT_STD_MOVE(BigInt_t(b).raw_sub(*this).inv());
        else
            raw_sub(b);
        return *this;
    }
    BigInt_t& inv() {
        sign = -sign;
        return *this;
    }
    BigInt_t operator-() const {
        return BIGINT_STD_MOVE(BigInt_t(*this).inv());
    }

    BigInt_t operator*(const BigInt_t &b) const {
        if (b.size() == 1) {
            BigInt_t r = *this;
            r.raw_mul_int((uint32_t)b.v[0]);
            r.sign *= b.sign;
            return BIGINT_STD_MOVE(r);
        } else if (v.size() == 1) {
            BigInt_t r = b;
            r.raw_mul_int((uint32_t)v[0]);
            r.sign *= sign;
            return BIGINT_STD_MOVE(r);
        } else {
            BigInt_t r;
            if (raw_less(b))
                r.raw_nttmul(*this, b);
            else
                r.raw_nttmul(b, *this);
            r.sign = sign * b.sign;
            return BIGINT_STD_MOVE(r);
        }
    }
    BigInt_t &operator*=(const BigInt_t &b) {
        if (b.size() == 1) {
            raw_mul_int((uint32_t)b.v[0]);
            sign *= b.sign;
            return *this;
        } else {
            return *this = *this * b;
        }
    }

    BigInt_t operator/(const BigInt_t &b) const {
        BigInt_t r, d;
        if (b.size() > BIGINT_DIV_THRESHOLD)
            d.raw_fastdiv(*this, b);
        else
            d.raw_dividediv(*this, b, r);
        d.sign = sign * b.sign;
        return BIGINT_STD_MOVE(d);
    }
    BigInt_t &operator/=(const BigInt_t &b) {
        if (this == &b) {
            return set(1);
        }
        return *this = *this / b;
    }
    BigInt_t operator%(const BigInt_t &b) const {
        if (b.size() == 1 && COMPRESS_MOD % b.v[0] == 0) {
            return BigInt_t((intmax_t)(v[0] % b.v[0]) * sign);
        }
        if (this == &b) {
            return BigInt_t((intmax_t)0);
        }
        return BIGINT_STD_MOVE(*this - *this / b * b);
    }
    BigInt_t &operator%=(const BigInt_t &b) {
        if (b.size() == 1 && COMPRESS_MOD % b.v[0] == 0) {
            return set(v[0] % b.v[0] * sign);
        }
        if (this == &b) {
            return set(0);
        }
        return *this = *this % b;
    }
    BigInt_t div(const BigInt_t &b, BigInt_t &r) {
        if (this == &b) {
            r.set(0);
            return set(1);
        }
        BigInt_t d;
        d.raw_fastdiv(*this, b);
        d.sign = sign * b.sign;
        r = *this - d * b;
        // d.raw_dividediv(*this, b, r);
        // d.sign = sign * b.sign;
        return BIGINT_STD_MOVE(d);
    }

    std::string to_str(int32_t out_base = 10, int32_t pack = 0) const {
        //{decm_e}
        if (out_base == 10) {
            //{decm_b}
            return out_dec();
            //{decm_e}
        }
        return out_mul(out_base, pack);
        //{decm_b}
    }
};
} // namespace BigIntDecNS

using BigIntDecNS::BigIntDec;