[Coursera]数据结构基础_Week2_线性表_Q3

#include<iostream>#include<string.h>using namespace std;class Error{public:Error(char* r) :reason(r) {}char* what() { return reason; }private:char* reason;};const int IntegerLen = 1000;class Integer{public:Integer(int num = 0);Integer(const Integer& obj);Integer operator = (const Integer& another);Integer operator + (const Integer& another) const;Integer operator - (const Integer& another) const;Integer operator - () const;Integer operator * (const Integer& another) const;Integer operator / (const Integer& another) const;Integer operator % (const Integer& another) const;bool operator > (const Integer& another) const;bool operator < (const Integer& another) const;bool operator == (const Integer& another) const;bool operator != (const Integer& another) const;bool operator >= (const Integer& another) const;bool operator <= (const Integer& another) const;friend ostream& operator << (ostream& stream, const Integer& obj);friend istream& operator >> (istream& stream, Integer& obj);private:Integer absolute() const;int IntegerLength() const;void augment(int n);int& operator [] (int index);const int& operator [] (int index) const;int NumArray[IntegerLen];int sign;};Integer::Integer(int num){if (num<0){sign = -1;num = -num;}else sign = 1;for (int i = 0; i<IntegerLen; i++){(*this)[i] = num % 10;num /= 10;}return;}Integer::Integer(const Integer& obj){sign = obj.sign;for (int i = 0; i<IntegerLen; i++) (*this)[i] = obj[i];return;}Integer Integer::operator = (const Integer& another){int i;(*this).sign = another.sign;for (i = 0; i<IntegerLen; i++)(*this)[i] = another[i];return *this;}Integer Integer::operator + (const Integer& another) const{int i;Integer result;if (sign == another.sign){for (i = 0; i<IntegerLen; i++){result[i] = (*this)[i] + another[i] + result[i];while (result[i] >= 10){result[i] -= 10;result[i + 1]++;}}result.sign = (*this).sign;}else result = (*this) - (-another);return result;}Integer Integer::operator - (const Integer& another) const{int i;Integer result;const Integer *max, *min;if ((*this) == another) return Integer(0);if (sign == another.sign){if ((*this).absolute()>another.absolute()){max = this;min = &another;}else{max = &another;min = this;}for (i = 0; i<IntegerLen; i++){result[i] = (*max)[i] - (*min)[i] + result[i];while (result[i]<0){result[i] += 10;result[i + 1]--;}}if (max == this) result.sign = (*this).sign;else result.sign = -(*this).sign;}else{result = (*this) + (-another);}return result;}Integer Integer::operator - () const{Integer result;result = *this;if (result != Integer(0))result.sign = -sign;return result;}Integer Integer::operator * (const Integer& another) const{Integer result, temp;int i, j;if ((*this) == 0 || another == 0) return result;for (i = 0; i<IntegerLen; i++){temp = Integer(0);for (j = 0; j<IntegerLen - i; j++){temp[i + j] = (*this)[i] * another[j] + temp[i + j];while (temp[i] >= 10){temp[i] -= 10;temp[i + 1]++;}}result = result + temp;}if (sign == another.sign) result.sign = 1;else result.sign = -1;return result;}Integer Integer::operator / (const Integer& another) const{if (another == Integer(0)) throw Error("Divisor can't be zero!");int i, j, margin;Integer result, dividend = (*this).absolute(), divisor = another.absolute();if (divisor>dividend) return Integer(0);i = IntegerLength();j = another.IntegerLength();margin = i - j;divisor.augment(margin);while (margin >= 0){if (dividend >= divisor){dividend = dividend - divisor;result.NumArray[IntegerLen - margin - 1]++;}else{margin--;divisor.augment(-1);}}if (sign == another.sign) result.sign = 1;else result.sign = -1;return result;}Integer Integer::operator % (const Integer& another) const{Integer result;result = (*this) - ((*this) / another)*another;return result;}bool Integer::operator > (const Integer& another) const{int i;if (sign>another.sign) return true;else if (sign<another.sign) return false;else if (sign == 1){for (i = IntegerLen - 1; i >= 0; i--)if ((*this)[i]>another[i]) return true;else if ((*this)[i]<another[i]) return false;}else{for (i = IntegerLen - 1; i >= 0; i--)if ((*this)[i]>another[i]) return false;else if ((*this)[i]<another[i]) return true;}return false;}bool Integer::operator < (const Integer& another) const{int i;if (sign>another.sign) return false;else if (sign<another.sign) return true;else if (sign == 1){for (i = IntegerLen - 1; i >= 0; i--)if ((*this)[i]>another[i]) return false;else if ((*this)[i]<another[i]) return true;}else{for (i = IntegerLen - 1; i >= 0; i--)if ((*this)[i]>another[i]) return true;else if ((*this)[i]<another[i]) return false;}return false;}bool Integer::operator == (const Integer& another) const{if (!(*this>another) && !(*this<another)) return true;else return false;}bool Integer::operator != (const Integer& another) const{if (*this == another) return false;else return true;}bool Integer::operator >= (const Integer& another) const{if (*this<another) return false;else return true;}bool Integer::operator <= (const Integer& another) const{if (*this>another) return false;else return true;}ostream& operator << (ostream& stream, const Integer& obj){int i;if (obj.sign == -1) stream << '-';for (i = 0; i<IntegerLen&&obj.NumArray[i] == 0; i++);if (i == IntegerLen) stream << 0;else for (; i<IntegerLen; i++) stream << obj.NumArray[i];return stream;}istream& operator >> (istream& stream, Integer& obj){int n, i;char input[IntegerLen];stream >> input;n = strlen(input);for (i = 0; n - i - 1>0; i++){if (input[n - i - 1]>'9' || input[n - i - 1]<'0') throw Error("Input Error!");obj[i] = input[n - i - 1] - '0';}if (input[n - i - 1] == '-') obj.sign = -1;else if (input[n - i - 1]>'9' || input[n - i - 1]<'0') throw Error("Input Error!");else obj[i] = input[n - 1 - i++] - '0';for (; i<IntegerLen; i++) obj[i] = 0;return stream;}Integer Integer::absolute() const{Integer result;result = *this;result.sign = 1;return result;}int Integer::IntegerLength() const{int i, result = 0;for (i = 0; i<IntegerLen&&NumArray[i] == 0; i++);result = IntegerLen - i;return result;}void Integer::augment(int n){int i;if (n >= 0){for (i = 0; i<IntegerLen; i++)if (i<IntegerLen - n) NumArray[i] = NumArray[i + n];else NumArray[i] = 0;}else{for (i = IntegerLen - 1; i >= 0; i--)if (i >= -n) NumArray[i] = NumArray[i + n];else NumArray[i] = 0;}}int& Integer::operator [] (int index){if (index<0 || index >= IntegerLen) throw Error("Out of Bounds!");return NumArray[IntegerLen - index - 1];}const int& Integer::operator [] (int index) const{if (index<0 || index >= IntegerLen) throw Error("Out of Bounds!");return NumArray[IntegerLen - index - 1];}int main(){Integer a, b;char s = '*';cin >> a >> b;switch (s){case'+':cout << a + b << endl; break;case'-':cout << a - b << endl; break;case'*':cout << a*b << endl; break;case'/':cout << a / b << endl; break;}return 0;}