C++大数模板
#include <bits/stdc++.h> using namespace std; class DividedByZeroException {}; class BigInteger { private: vector<char> digits; bool sign; // true for positive, false for negitive void trim(); // remove zeros in tail, but if the value is 0, keep only one:) public: BigInteger(int); // construct with a int integer BigInteger(string&) ; BigInteger(); BigInteger(const BigInteger&); BigInteger operator=(const BigInteger& op2); BigInteger abs() const; BigInteger pow(int a); //binary operators friend BigInteger operator+=(BigInteger&, const BigInteger&); friend BigInteger operator-=(BigInteger&, const BigInteger&); friend BigInteger operator*=(BigInteger&, const BigInteger&); friend BigInteger operator/=(BigInteger&, const BigInteger&) throw(DividedByZeroException); friend BigInteger operator%=(BigInteger&, const BigInteger&) throw(DividedByZeroException); friend BigInteger operator+(const BigInteger&, const BigInteger&); friend BigInteger operator-(const BigInteger&, const BigInteger&); friend BigInteger operator*(const BigInteger&, const BigInteger&); friend BigInteger operator/(const BigInteger&, const BigInteger&) throw(DividedByZeroException); friend BigInteger operator%(const BigInteger&, const BigInteger&) throw(DividedByZeroException); //uniary operators friend BigInteger operator-(const BigInteger&); //negative friend BigInteger operator++(BigInteger&); //++v friend BigInteger operator++(BigInteger&, int); //v++ friend BigInteger operator--(BigInteger&); //--v friend BigInteger operator--(BigInteger&, int); //v-- friend bool operator>(const BigInteger&, const BigInteger&); friend bool operator<(const BigInteger&, const BigInteger&); friend bool operator==(const BigInteger&, const BigInteger&); friend bool operator!=(const BigInteger&, const BigInteger&); friend bool operator>=(const BigInteger&, const BigInteger&); friend bool operator<=(const BigInteger&, const BigInteger&); friend ostream& operator<<(ostream&, const BigInteger&); //print the BigInteger friend istream& operator>>(istream&, BigInteger&); // input the BigInteger public: static const BigInteger ZERO; static const BigInteger ONE; static const BigInteger TEN; }; const BigInteger BigInteger::ZERO = BigInteger(0); const BigInteger BigInteger::ONE = BigInteger(1); const BigInteger BigInteger::TEN = BigInteger(10); BigInteger::BigInteger() { sign = true; } BigInteger::BigInteger(int val) { // construct with a int integer if (val >= 0) { sign = true; } else { sign = false; val *= (-1); } do { digits.push_back((char)(val % 10)); val /= 10; } while (val != 0); } BigInteger::BigInteger(string& def) { sign = true; for (string::reverse_iterator iter = def.rbegin() ; iter < def.rend(); iter++) { char ch = (*iter); if (iter == def.rend() - 1) { if (ch == '+') { break; } if (ch == '-') { sign = false; break; } } digits.push_back((char)((*iter) - '0')); } trim(); } void BigInteger::trim() { vector<char>::reverse_iterator iter = digits.rbegin(); while (!digits.empty() && (*iter) == 0) { digits.pop_back(); iter = digits.rbegin(); } if (digits.size() == 0) { sign = true; digits.push_back(0); } } BigInteger::BigInteger(const BigInteger& op2) { sign = op2.sign; digits = op2.digits; } BigInteger BigInteger::operator=(const BigInteger& op2) { digits = op2.digits; sign = op2.sign; return (*this); } BigInteger BigInteger::abs() const { if (sign) { return *this; } else { return -(*this); } } BigInteger BigInteger::pow(int a) { BigInteger res(1); for (int i = 0; i < a; i++) { res *= (*this); } return res; } //binary operators BigInteger operator+=(BigInteger& op1, const BigInteger& op2) { if (op1.sign == op2.sign) { //只处理相同的符号的情况，异号的情况给-处理 vector<char>::iterator iter1; vector<char>::const_iterator iter2; iter1 = op1.digits.begin(); iter2 = op2.digits.begin(); char to_add = 0; //进位 while (iter1 != op1.digits.end() && iter2 != op2.digits.end()) { (*iter1) = (*iter1) + (*iter2) + to_add; to_add = ((*iter1) > 9); // 大于9进一位 (*iter1) = (*iter1) % 10; iter1++; iter2++; } while (iter1 != op1.digits.end()) { // (*iter1) = (*iter1) + to_add; to_add = ((*iter1) > 9); (*iter1) %= 10; iter1++; } while (iter2 != op2.digits.end()) { char val = (*iter2) + to_add; to_add = (val > 9) ; val %= 10; op1.digits.push_back(val); iter2++; } if (to_add != 0) { op1.digits.push_back(to_add); } return op1; } else { if (op1.sign) { return op1 -= (-op2); } else { return op1 = op2 - (-op1); } } } BigInteger operator-=(BigInteger& op1, const BigInteger& op2) { if (op1.sign == op2.sign) { //只处理相同的符号的情况，异号的情况给+处理 if (op1.sign) { if (op1 < op2) { // 2 - 3 return op1 = -(op2 - op1); } } else { if (-op1 > -op2) { // (-3)-(-2) = -(3 - 2) return op1 = -((-op1) - (-op2)); } else { // (-2)-(-3) = 3 - 2 return op1 = (-op2) - (-op1); } } vector<char>::iterator iter1; vector<char>::const_iterator iter2; iter1 = op1.digits.begin(); iter2 = op2.digits.begin(); char to_substract = 0; //借位 while (iter1 != op1.digits.end() && iter2 != op2.digits.end()) { (*iter1) = (*iter1) - (*iter2) - to_substract; to_substract = 0; if ((*iter1) < 0) { to_substract = 1; (*iter1) += 10; } iter1++; iter2++; } while (iter1 != op1.digits.end()) { (*iter1) = (*iter1) - to_substract; to_substract = 0; if ((*iter1) < 0) { to_substract = 1; (*iter1) += 10; } else { break; } iter1++; } op1.trim(); return op1; } else { if (op1 > BigInteger::ZERO) { return op1 += (-op2); } else { return op1 = -(op2 + (-op1)); } } } BigInteger operator*=(BigInteger& op1, const BigInteger& op2) { BigInteger result(0); if (op1 == BigInteger::ZERO || op2 == BigInteger::ZERO) { result = BigInteger::ZERO; } else { vector<char>::const_iterator iter2 = op2.digits.begin(); while (iter2 != op2.digits.end()) { if (*iter2 != 0) { deque<char> temp(op1.digits.begin(), op1.digits.end()); char to_add = 0; deque<char>::iterator iter1 = temp.begin(); while (iter1 != temp.end()) { (*iter1) *= (*iter2); (*iter1) += to_add; to_add = (*iter1) / 10; (*iter1) %= 10; iter1++; } if (to_add != 0) { temp.push_back(to_add); } int num_of_zeros = iter2 - op2.digits.begin(); while (num_of_zeros--) { temp.push_front(0); } BigInteger temp2; temp2.digits.insert(temp2.digits.end(), temp.begin(), temp.end()); temp2.trim(); result = result + temp2; } iter2++; } result.sign = ((op1.sign && op2.sign) || (!op1.sign && !op2.sign)); } op1 = result; return op1; } BigInteger operator/=(BigInteger& op1, const BigInteger& op2) throw(DividedByZeroException) { if (op2 == BigInteger::ZERO) { throw DividedByZeroException(); } BigInteger t1 = op1.abs(), t2 = op2.abs(); if (t1 < t2) { op1 = BigInteger::ZERO; return op1; } //现在 t1 > t2 > 0 //只需将 t1/t2的结果交给result就可以了 deque<char> temp; vector<char>::reverse_iterator iter = t1.digits.rbegin(); BigInteger temp2(0); while (iter != t1.digits.rend()) { temp2 = temp2 * BigInteger::TEN + BigInteger((int)(*iter)); char s = 0; while (temp2 >= t2) { temp2 = temp2 - t2; s = s + 1; } temp.push_front(s); iter++; } op1.digits.clear(); op1.digits.insert(op1.digits.end(), temp.begin(), temp.end()); op1.trim(); op1.sign = ((op1.sign && op2.sign) || (!op1.sign && !op2.sign)); return op1; } BigInteger operator%=(BigInteger& op1, const BigInteger& op2) throw(DividedByZeroException) { return op1 -= ((op1 / op2) * op2); } BigInteger operator+(const BigInteger& op1, const BigInteger& op2) { BigInteger temp(op1); temp += op2; return temp; } BigInteger operator-(const BigInteger& op1, const BigInteger& op2) { BigInteger temp(op1); temp -= op2; return temp; } BigInteger operator*(const BigInteger& op1, const BigInteger& op2) { BigInteger temp(op1); temp *= op2; return temp; } BigInteger operator/(const BigInteger& op1, const BigInteger& op2) throw(DividedByZeroException) { BigInteger temp(op1); temp /= op2; return temp; } BigInteger operator%(const BigInteger& op1, const BigInteger& op2) throw(DividedByZeroException) { BigInteger temp(op1); temp %= op2; return temp; } //uniary operators BigInteger operator-(const BigInteger& op) { //negative BigInteger temp = BigInteger(op); temp.sign = !temp.sign; return temp; } BigInteger operator++(BigInteger& op) { //++v op += BigInteger::ONE; return op; } BigInteger operator++(BigInteger& op, int x) { //v++ BigInteger temp(op); ++op; return temp; } BigInteger operator--(BigInteger& op) { //--v op -= BigInteger::ONE; return op; } BigInteger operator--(BigInteger& op, int x) { //v-- BigInteger temp(op); --op; return temp; } bool operator<(const BigInteger& op1, const BigInteger& op2) { if (op1.sign != op2.sign) { return !op1.sign; } else { if (op1.digits.size() != op2.digits.size()) return (op1.sign && op1.digits.size() < op2.digits.size()) || (!op1.sign && op1.digits.size() > op2.digits.size()); vector<char>::const_reverse_iterator iter1, iter2; iter1 = op1.digits.rbegin(); iter2 = op2.digits.rbegin(); while (iter1 != op1.digits.rend()) { if (op1.sign && *iter1 < *iter2) { return true; } if (op1.sign && *iter1 > *iter2) { return false; } if (!op1.sign && *iter1 > *iter2) { return true; } if (!op1.sign && *iter1 < *iter2) { return false; } iter1++; iter2++; } return false; } } bool operator==(const BigInteger& op1, const BigInteger& op2) { if (op1.sign != op2.sign || op1.digits.size() != op2.digits.size()) { return false; } vector<char>::const_iterator iter1, iter2; iter1 = op1.digits.begin(); iter2 = op2.digits.begin(); while (iter1 != op1.digits.end()) { if (*iter1 != *iter2) { return false; } iter1++; iter2++; } return true; } bool operator!=(const BigInteger& op1, const BigInteger& op2) { return !(op1 == op2); } bool operator>=(const BigInteger& op1, const BigInteger& op2) { return (op1 > op2) || (op1 == op2); } bool operator<=(const BigInteger& op1, const BigInteger& op2) { return (op1 < op2) || (op1 == op2); } bool operator>(const BigInteger& op1, const BigInteger& op2) { return !(op1 <= op2); } ostream& operator<<(ostream& stream, const BigInteger& val) { //print the BigInteger if (!val.sign) { stream << "-"; } for (vector<char>::const_reverse_iterator iter = val.digits.rbegin(); iter != val.digits.rend() ; iter++) { stream << (char)((*iter) + '0'); } return stream; } istream& operator>>(istream& stream, BigInteger& val) { //Input the BigInteger string str; stream >> str; val = BigInteger(str); return stream; } int main() { BigInteger A; BigInteger B; BigInteger C = 888; cin >> A >> B; cout << "A-B:" << A - B << endl; cout << "A+B:" << A + B << endl; cout << "A*B:" << A*B << endl; cout << "A/B:" << A / B << endl; cout << "A%B:" << A % B << endl; cout << "A.pow(5)" << A.pow(5) << endl; A++; cout << "A++:" << A << endl; A--; cout << "A--:" << A << endl; cout << "++B:" << ++B << endl; cout << "--B:" << --B << endl; cout << "C:" << C << endl; }
支持
=、abs()、pow()、+=、-=
*=、/=、%=、+、-、*、/
++、--、大小比较、输入输出流
其中涉及除法或者模运算的可抛出除数为0的异常
