/** * @file int2048.cpp --- 2048-bit integer class implementation * * @details This file contains the implementation of the 2048-bit integer class. * * Codesytle: This file is written in a sytle mainly based on Google C++ Style * Guide. As I use Clang-format to format my code, so the code style may be a * little bit strange sometimes, in that case I'll manually format the * code.What's sepecial is the comment: * 1. Multi-line comments are always before the code they comment on. * Usually the code they comment on is a complex procedure,like the definition * of a function,a class or a variable with complex operation. If a multi-line * comment is in one line, it will start with "/*" instead of "/**",otherwise it * will start with "/**" and in the format of Doxygen. * 2. Single-line comments are always after the code they comment on. * Usually they are in the same line with the code they comment on,but sometimes * they may come in the next lines. single-line comments shouldn't exceed 3 * lines as they are intended to be short and easy to understand. * 3. Temporary disabled code will be marked with "//" in the front of each * 4. Some comments have special meanings,like "//TODO", "//FIXME", "//XXX","// * clang-format off" and "// clang-format on". They are not controlled by the * previous rules. */ #include "int2048.h" #include #include #include static_assert(sizeof(int) == 4, "sizeof(int) != 4"); static_assert(sizeof(long long) == 8, "sizeof(long long)!=8"); namespace sjtu { // 构造函数 int2048::int2048() { // 实现构造函数逻辑 buf_length = kDefaultLength; val = new int[buf_length](); flag = 1; num_length = 1; } int2048::~int2048() { // 实现析构函数逻辑 if (val != nullptr) delete[] val; } int2048::int2048(long long input_value) { // 实现构造函数逻辑 buf_length = kDefaultLength; val = new int[buf_length](); if (input_value < 0) { flag = -1; input_value = -input_value; } else flag = 1; if (input_value == 0) { num_length = 1; return; } num_length = 0; const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; while (input_value > 0) { val[num_length / kNum] += (input_value % 10) * kPow10[num_length % kNum]; input_value /= 10; num_length++; } } int2048::int2048(const std::string &input_value) { // 实现构造函数逻辑 buf_length = (input_value.length() + kNum - 1) / kNum * kMemAdditionScalar; val = new int[buf_length](); flag = 1; num_length = 0; if (input_value[0] == '-') { flag = -1; } const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; int read_highest_pos = (flag > 0 ? 0 : 1); while (input_value[read_highest_pos] == '0' && read_highest_pos + 1 < input_value.length()) read_highest_pos++; for (int i = input_value.length() - 1; i >= read_highest_pos; i--) { val[num_length / kNum] += (input_value[i] - '0') * kPow10[num_length % kNum]; num_length++; } if (num_length == 1 && val[0] == 0) flag = 1; } int2048::int2048(const int2048 &input_value) { buf_length = input_value.buf_length; val = new int[buf_length](); memcpy(val, input_value.val, buf_length * sizeof(int)); flag = input_value.flag; num_length = input_value.num_length; } int2048::int2048(int2048 &&input_value) noexcept { buf_length = input_value.buf_length; val = input_value.val; flag = input_value.flag; num_length = input_value.num_length; input_value.val = nullptr; } // 读入一个大整数 void int2048::read(const std::string &input_value) { delete[] val; buf_length = (input_value.length() + kNum - 1) / kNum * kMemAdditionScalar; val = new int[buf_length](); flag = 1; num_length = 0; if (input_value[0] == '-') { flag = -1; } const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; int read_highest_pos = (flag > 0 ? 0 : 1); while (input_value[read_highest_pos] == '0' && read_highest_pos + 1 < input_value.length()) read_highest_pos++; for (int i = input_value.length() - 1; i >= read_highest_pos; i--) { val[num_length / kNum] += (input_value[i] - '0') * kPow10[num_length % kNum]; num_length++; } if (num_length == 1 && val[0] == 0) flag = 1; } // 输出储存的大整数,无需换行 void int2048::print() { // 实现输出逻辑 if (flag == -1) putchar('-'); const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; for (int i = num_length - 1; i >= 0; i--) putchar('0' + val[i / kNum] / kPow10[i % kNum] % 10); } void int2048::ClaimMem(size_t number_length) { size_t new_number_blocks = (number_length + kNum - 1) / kNum; if (new_number_blocks > buf_length) { int *new_val = new int[new_number_blocks * kMemAdditionScalar](); memcpy(new_val, val, buf_length * sizeof(int)); delete[] val; val = new_val; buf_length = new_number_blocks * kMemAdditionScalar; } else if (new_number_blocks * kMemDeleteScalar < buf_length) { int *new_val = new int[new_number_blocks * kMemAdditionScalar](); memcpy(new_val, val, new_number_blocks * sizeof(int)); delete[] val; val = new_val; buf_length = new_number_blocks * kMemAdditionScalar; } } inline int UnsignedCmp(const int2048 &A, const int2048 &B) { if (A.num_length != B.num_length) return A.num_length < B.num_length ? -1 : 1; int number_of_blocks = (A.num_length + int2048::kNum - 1) / int2048::kNum; for (int i = number_of_blocks - 1; i >= 0; i--) if (A.val[i] != B.val[i]) return A.val[i] < B.val[i] ? -1 : 1; return 0; } inline void UnsignedAdd(int2048 &A, const int2048 *const pB) { if (&A == pB) throw "UnsignedAdd: A and B are the same object"; A.ClaimMem(std::max(A.num_length, pB->num_length) + 2); for (int i = 0; i < (std::max(A.num_length, pB->num_length) + int2048::kNum - 1) / int2048::kNum; i++) { if (i < (pB->num_length + int2048::kNum - 1) / int2048::kNum) A.val[i] += pB->val[i]; A.val[i + 1] += A.val[i] / int2048::kMod; A.val[i] %= int2048::kMod; } A.num_length = std::max(A.num_length, pB->num_length); const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; if (A.val[A.num_length / int2048::kNum] / kPow10[A.num_length % int2048::kNum] > 0) A.num_length++; } // 加上一个大整数 int2048 &int2048::add(const int2048 &B) { // 实现加法逻辑 const int2048 *pB = &B; if (this->flag == pB->flag) { if (this == &B) pB = new int2048(B); UnsignedAdd(*this, pB); } else if (this->flag == 1 && pB->flag == -1) { int cmp = UnsignedCmp(*this, *pB); if (cmp >= 0) { if (this == &B) pB = new int2048(B); UnsignedMinus(*this, pB); this->flag = 1; } else { int2048 new_B = std::move(*this); *this = B; UnsignedMinus(*this, &new_B); this->flag = -1; } } else if (this->flag == -1 && pB->flag == 1) { int cmp = UnsignedCmp(*this, *pB); if (cmp >= 0) { if (this == &B) pB = new int2048(B); UnsignedMinus(*this, pB); this->flag = -1; if (this->num_length == 1 && this->val[0] == 0) this->flag = 1; } else { int2048 new_B = std::move(*this); *this = B; UnsignedMinus(*this, &new_B); this->flag = 1; } } return *this; } // 返回两个大整数之和 int2048 add(int2048 A, const int2048 &B) { // 实现加法逻辑 return std::move(A.add(B)); } inline void UnsignedMinus(int2048 &A, const int2048 *const pB) { if (&A == pB) throw "UnsignedMinus: A and B are the same object"; for (int i = 0; i < (pB->num_length + int2048::kNum - 1) / int2048::kNum; i++) { A.val[i] -= pB->val[i]; if (A.val[i] < 0) { A.val[i] += int2048::kMod; A.val[i + 1]--; } } const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; int new_length = 0; for (int i = 0; i < A.num_length; i++) if (A.val[i / int2048::kNum] / kPow10[i % int2048::kNum] > 0) new_length = i + 1; A.num_length = new_length; if (A.num_length == 0) A.num_length = 1; A.ClaimMem(A.num_length); } // 减去一个大整数 int2048 &int2048::minus(const int2048 &B) { // 实现减法逻辑 const int2048 *pB = &B; if (this->flag == B.flag) { int cmp = UnsignedCmp(*this, *pB); if (cmp >= 0) { if (this == &B) pB = new int2048(B); UnsignedMinus(*this, pB); if (this->num_length == 1 && this->val[0] == 0) this->flag = 1; } else { int2048 new_B = std::move(*this); *this = B; UnsignedMinus(*this, &new_B); this->flag = -this->flag; if (this->num_length == 1 && this->val[0] == 0) this->flag = 1; } } else { if (this == &B) pB = new int2048(B); UnsignedAdd(*this, pB); } return *this; } // 返回两个大整数之差 int2048 minus(int2048 A, const int2048 &B) { // 实现减法逻辑 return std::move(A.minus(B)); } // 运算符重载 int2048 int2048::operator+() const { // 实现一元加法逻辑 return std::move(int2048(*this)); } int2048 int2048::operator-() const { // 实现一元减法逻辑 int2048 ret(*this); if (!(ret.num_length == 1 && ret.val[0] == 0)) ret.flag = -ret.flag; return std::move(ret); } int2048 &int2048::operator=(const int2048 &B) { // 实现赋值运算符逻辑 // similar to int2048::int2048(const int2048 &input_value) if (this == &B) return *this; delete[] val; buf_length = B.buf_length; val = new int[buf_length](); memcpy(val, B.val, buf_length * sizeof(int)); flag = B.flag; num_length = B.num_length; return *this; } int2048 &int2048::operator=(int2048 &&B) noexcept { // 实现移动赋值运算符逻辑 if (this == &B) return *this; delete[] val; buf_length = B.buf_length; val = B.val; flag = B.flag; num_length = B.num_length; B.val = nullptr; return *this; } int2048 &int2048::operator+=(const int2048 &B) { // 实现复合加法逻辑 return this->add(B); } int2048 operator+(int2048 A, const int2048 &B) { // 实现加法逻辑 A.add(B); return std::move(A); } int2048 &int2048::operator-=(const int2048 &B) { // 实现复合减法逻辑 return this->minus(B); } int2048 operator-(int2048 A, const int2048 &B) { // 实现减法逻辑 A.minus(B); return std::move(A); } __int128_t int2048::QuickPow(__int128_t v, long long q) { __int128_t ret = 1; v %= int2048::kNTTMod; while (q > 0) { if (q & 1) (ret *= v) %= int2048::kNTTMod; (v *= v) %= int2048::kNTTMod; q >>= 1; } return ret; } void int2048::NTTTransform(__int128_t *a, int NTT_blocks, bool inverse = false) { for (int i = 1, j = 0; i < NTT_blocks; i++) { int bit = NTT_blocks >> 1; while (j >= bit) { j -= bit; bit >>= 1; } j += bit; if (i < j) std::swap(a[i], a[j]); } for (int len = 2; len <= NTT_blocks; len <<= 1) { __int128_t wlen = QuickPow(int2048::kNTTRoot, (int2048::kNTTMod - 1) / len); if (inverse) wlen = QuickPow(wlen, int2048::kNTTMod - 2); for (int i = 0; i < NTT_blocks; i += len) { __int128_t w = 1; for (int j = 0; j < len / 2; j++) { __int128_t u = a[i + j], v = a[i + j + len / 2] * w % int2048::kNTTMod; a[i + j] = (u + v) % int2048::kNTTMod; a[i + j + len / 2] = (u - v + int2048::kNTTMod) % int2048::kNTTMod; (w *= wlen) %= int2048::kNTTMod; } } } if (inverse) { __int128_t inv = QuickPow(NTT_blocks, int2048::kNTTMod - 2); for (int i = 0; i < NTT_blocks; i++) (a[i] *= inv) %= int2048::kNTTMod; } } inline void UnsignedMultiply(int2048 &A, const int2048 *pB) { if (&A == pB) throw "UnsignedMultiply: A and B are the same object"; int blocks_of_A = ((A.num_length + int2048::kNum - 1) / int2048::kNum); int blocks_of_B = ((pB->num_length + int2048::kNum - 1) / int2048::kNum); int max_blocks = blocks_of_A + blocks_of_B; int NTT_blocks = 1; while (NTT_blocks < (max_blocks << 1)) NTT_blocks <<= 1; __int128_t *pDA = new __int128_t[NTT_blocks](); __int128_t *pDB = new __int128_t[NTT_blocks](); __int128_t *pDC = new __int128_t[NTT_blocks](); for (int i = 0; i < blocks_of_A; i++) { pDA[i << 1] = A.val[i] % int2048::kNTTBlcokBase; pDA[(i << 1) | 1] = A.val[i] / int2048::kNTTBlcokBase; } for (int i = 0; i < blocks_of_B; i++) { pDB[i << 1] = pB->val[i] % int2048::kNTTBlcokBase; pDB[(i << 1) | 1] = pB->val[i] / int2048::kNTTBlcokBase; } A.NTTTransform(pDA, NTT_blocks); A.NTTTransform(pDB, NTT_blocks); for (int i = 0; i < NTT_blocks; i++) pDC[i] = (pDA[i] * pDB[i]) % int2048::kNTTMod; A.NTTTransform(pDC, NTT_blocks, true); for (int i = 0; i < NTT_blocks - 1; i++) { pDC[i + 1] += pDC[i] / int2048::kNTTBlcokBase; pDC[i] %= int2048::kNTTBlcokBase; } if (pDC[NTT_blocks - 1] >= int2048::kNTTBlcokBase) throw "UnsignedMultiply: NTT result overflow"; int flag_store = A.flag; A.ClaimMem(NTT_blocks * 4); memset(A.val, 0, A.buf_length * sizeof(int)); for (int i = 0; i < NTT_blocks / 2; i++) { A.val[i] = pDC[(i << 1) | 1] * int2048::kNTTBlcokBase + pDC[i << 1]; } A.num_length = NTT_blocks * 4; const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; while (A.val[(A.num_length - 1) / int2048::kNum] / kPow10[(A.num_length - 1) % int2048::kNum] == 0) { A.num_length--; if (A.num_length == 0) throw "UnsignedMultiply: num_length==0"; } delete[] pDA; delete[] pDB; delete[] pDC; } int2048 &int2048::Multiply(const int2048 &B) { // 实现复合乘法逻辑 const int2048 *pB = &B; if (this == &B) pB = new int2048(B); if ((this->num_length == 1 && this->val[0] == 0) || (pB->num_length == 1 && pB->val[0] == 0)) { *this = std::move(int2048(0)); return *this; } this->flag = this->flag * pB->flag; UnsignedMultiply(*this, pB); return *this; } int2048 Multiply(int2048 A, const int2048 &B) { // 实现乘法逻辑 return std::move(A.Multiply(B)); } int2048 &int2048::operator*=(const int2048 &B) { // 实现复合乘法逻辑 return this->Multiply(B); } int2048 operator*(int2048 A, const int2048 &B) { // 实现乘法逻辑 A.Multiply(B); return std::move(A); } int2048 &int2048::operator/=(const int2048 &) { // 实现复合除法逻辑 } int2048 operator/(int2048, const int2048 &) { // 实现除法逻辑 } int2048 &int2048::operator%=(const int2048 &) { // 实现复合取模逻辑 } int2048 operator%(int2048, const int2048 &) { // 实现取模逻辑 } std::istream &operator>>(std::istream &stream, int2048 &V) { // 实现输入运算符逻辑 std::string v_str; stream >> v_str; V.read(v_str); return stream; } std::ostream &operator<<(std::ostream &stream, const int2048 &v) { // 实现输出运算符逻辑 if (v.flag == -1) stream << '-'; const static int kPow10[9] = {1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000}; for (int i = v.num_length - 1; i >= 0; i--) stream << char('0' + v.val[i / int2048::kNum] / kPow10[i % int2048::kNum] % 10); return stream; } bool operator==(const int2048 &A, const int2048 &B) { // 实现等于运算符逻辑 if (A.flag != B.flag) return false; return UnsignedCmp(A, B) == 0; } bool operator!=(const int2048 &A, const int2048 &B) { // 实现不等于运算符逻辑 if (A.flag != B.flag) return true; return UnsignedCmp(A, B) != 0; } bool operator<(const int2048 &A, const int2048 &B) { // 实现小于运算符逻辑 if (A.flag != B.flag) return A.flag < B.flag; int cmp = UnsignedCmp(A, B); if (A.flag == 1) return cmp < 0; else return cmp > 0; } bool operator>(const int2048 &A, const int2048 &B) { // 实现大于运算符逻辑 if (A.flag != B.flag) return A.flag > B.flag; int cmp = UnsignedCmp(A, B); if (A.flag == 1) return cmp > 0; else return cmp < 0; } bool operator<=(const int2048 &A, const int2048 &B) { // 实现小于等于运算符逻辑 if (A.flag != B.flag) return A.flag < B.flag; int cmp = UnsignedCmp(A, B); if (A.flag == 1) return cmp <= 0; else return cmp >= 0; } bool operator>=(const int2048 &A, const int2048 &B) { // 实现大于等于运算符逻辑 if (A.flag != B.flag) return A.flag > B.flag; int cmp = UnsignedCmp(A, B); if (A.flag == 1) return cmp >= 0; else return cmp <= 0; } } // namespace sjtu