重载运算符

来源：互联网发布：c语言界面设计编辑：程序博客网时间：2024/05/17 22:26
重载运算符

–运算符重载，就是对已有的运算符重新进行定义，赋予其另一种功能，以适应不同的数据类型。

此处有高精度+ - * / % > < >= <= ==
不要在意头文件。。
本篇的高精度自带正负
用动态数组存储
不用考虑位数的问题
只要空间不超限就行
#include<bits/stdc++.h>using namespace std;struct BigInt{    bool symbol;    vector<int>num;    BigInt(string sNum = "0"){*this=sNum;}    BigInt(int iNum){*this = iNum;}         BigInt operator=(const int iNum)    {        num.erase(num.begin(), num.end());                      int tmp(iNum);                if(iNum < 0)symbol=true,tmp=-tmp;         else symbol=false;        while(tmp >= 10){num.push_back(tmp % 10);tmp /= 10;}                if(tmp!=0)num.push_back(tmp);        else if(num.empty())num.push_back(0);        return *this;    }    BigInt operator = (const string sNum)        {                  num.erase(num.begin(), num.end());        for(string::size_type i(sNum.size() - 1); i > 0; --i)num.push_back(sNum[i] - '0');        if(sNum[0] == '-')symbol=true;        else{symbol=false;num.push_back(sNum[0] - '0');}        for(vector<int>::size_type i(num.size() - 1); num[i] == 0 && i > 0; --i)            num.pop_back();                return *this;    }    BigInt operator = (const BigInt bInt)        {        num.erase(num.begin(), num.end());        for(vector<int>::size_type i(0); i < bInt.num.size(); ++i)num.push_back(bInt.num[i]);        symbol=bInt.symbol;                return *this;        }         BigInt operator+(const BigInt bInt)const    {        BigInt rslt;        if(bInt.symbol == (*this).symbol)              if(bInt.symbol)rslt.symbol=true;        else if((*this).symbol){rslt=bInt-(-*this);rslt.symbol=true;return rslt;}                else if(bInt.symbol){rslt = *this - (-bInt);return rslt;}              vector<int>::size_type lenA(num.size()), lenB(bInt.num.size()), lng;                lng = (lenA > lenB ? lenA : lenB);              for(vector<int>::size_type i(0); i < lng; ++i)                {                        int tmp(rslt.num[rslt.num.size() - 1]);                  if(i<lenA)tmp+=num[i];                        if(i<lenB)tmp+=bInt.num[i];                        rslt.num[rslt.num.size() - 1] = tmp % 10;                    rslt.num.push_back(tmp / 10);              }                if(rslt.num[lng]==0)rslt.num.pop_back();             return rslt;        }    BigInt operator - (BigInt bInt) const        {               BigInt rslt, myInt(*this), tmp;                    vector<int>::size_type lenA(num.size()), lenB(bInt.num.size()), lng, shrt, len;                shrt=(lenA > lenB ? lenB : lenA);             lng=(lenA > lenB ? lenA : lenB);                    if(bInt.symbol == myInt.symbol)                {            if(!bInt.symbol)                    {                                if(myInt < bInt)                                {                                        tmp = myInt; myInt = bInt; bInt = tmp;                    rslt.symbol = true;                                }                        }                        else                     {                                if(myInt > bInt)                                {                                        tmp = myInt; myInt = bInt; bInt = tmp;                    rslt.symbol = false;                                }                myInt=-myInt;bInt=-bInt;                rslt.symbol = true;                        }        }        else if(myInt.symbol) return -(-myInt + bInt);        else if(bInt.symbol) return myInt + (-bInt);                   for(vector<int>::size_type i(0); i < lng; ++i)                {                        if(i < shrt)                        {                              if(myInt.num[i] < bInt.num[i])                                {                                      myInt.num[i + 1] -= 1;                                        rslt.num[i] = myInt.num[i] + 10 - bInt.num[i];                              }                                else rslt.num[i] = myInt.num[i] - bInt.num[i];                    }                        else rslt.num[i] = myInt.num[i];                        rslt.num.push_back(0);                }                   for(vector<int>::size_type i(rslt.num.size() - 1); rslt.num[i] == 0 && i > 0; --i)                        rslt.num.pop_back();        return rslt;        }    BigInt operator - () const        {                BigInt rslt(*this);                if(rslt != 0)             rslt.symbol = !rslt.symbol;                return rslt;        }         BigInt operator * (const BigInt bInt) const        {                BigInt rslt;                   vector<int>::size_type lenA(num.size()), lenB(bInt.num.size()), len(lenA + lenB);                rslt.num.insert(rslt.num.begin(), len - 1, 0);             for(vector<int>::size_type i(0); i < lenA; ++i)                        for(vector<int>::size_type j(0); j < lenB; ++j)                        {                                rslt.num[i + j] += num[i] * bInt.num[j];                                rslt.num[i + j + 1] += rslt.num[i + j] / 10;                                rslt.num[i + j] %= 10;                        }                    if(rslt.num[len - 1] == 0)                 rslt.num.pop_back();                if(rslt != 0)                 rslt.symbol = symbol ^ bInt.symbol;                    return rslt;        }         BigInt operator / (const BigInt bInt) const        {               BigInt tmp, tmp2;                string rsltS((*this).num.size(), '0');                if(bInt == 0) return BigInt(0);                vector<int>::size_type i(num.size());                string::size_type j(0);                while(i--)                {                        if(tmp == 0)                 tmp.num.pop_back();                        tmp.num.insert(tmp.num.begin(), num[i]);                  int i(10);                        while(i--)                    {                                tmp2 = tmp - (bInt < 0 ? -bInt : bInt) * i;                          if(tmp2 >= 0)                            {                                        rsltS[j] += i;                                  tmp = tmp2;                                        break;                                }                        }                       ++j;                }                BigInt rslt(rsltS);            if(rslt != 0)             rslt.symbol = symbol ^ bInt.symbol;                return rslt;        }         BigInt operator % (const BigInt bInt) const        {                BigInt rslt, tmp;                if(*this == 0)             return BigInt(0);        vector<int>::size_type i(num.size());                while(i--)                {                        if(rslt == 0)                 rslt.num.pop_back();                        rslt.num.insert(rslt.num.begin(), num[i]);                int i(10);                        while(i--)                   {                                tmp = rslt - (bInt < 0 ? -bInt : bInt) * i;                                if(tmp >= 0)                           {                                        rslt = tmp;                                        break;                                }                        }                }                  rslt.symbol = symbol;                return rslt;        }          BigInt operator += (const BigInt bInt)        {                *this = *this + bInt;                return *this;        }         BigInt operator -= (const BigInt bInt)        {                *this = *this - bInt;                return *this;        }          BigInt operator *= (const BigInt bInt)        {                *this = *this * bInt;                return *this;        }        BigInt operator /= (const BigInt bInt)        {                *this = *this / bInt;                return *this;        }          BigInt operator %= (const BigInt bInt)        {                *this = *this % bInt;               return *this;        }          bool operator < (const BigInt bInt) const        {                vector<int>::size_type bLen(bInt.num.size());                         if(!bInt.symbol && symbol)              return true;              else if(bInt.symbol && !symbol)             return false;               else if(num.size() != bLen)          {                        if(!symbol)                 return num.size() < bLen;                        else                 return num.size() > bLen;                }                  for(vector<int>::size_type i(bLen - 1); i > 0; --i)                {                        if(num[i] != bInt.num[i])                        {                                if(!bInt.symbol && !(*this).symbol)                     return num[i] < bInt.num[i];                               else                     return bInt.num[i] < num[i];                        }                }                if(!bInt.symbol && !symbol)             return num[0] < bInt.num[0];             else             return bInt.num[0] < num[0];    }           bool operator>(const BigInt bInt)const{return bInt<*this;}         bool operator <= (const BigInt bInt)const{return !(*this > bInt);}    bool operator >= (const BigInt bInt)const{return !(*this < bInt);}             bool operator != (const BigInt bInt)const{return (*this<bInt)||(*this>bInt);}         bool operator == (const BigInt bInt)const{return !(*this != bInt);}}; istream& operator >> (istream &in, BigInt& x){        string tmp;    in >> tmp;    x = tmp;    return in;} ostream& operator << (ostream &out, BigInt& x){        if(x.symbol)cout<<'-';          for(vector<int>::size_type i(x.num.size() - 1); i > 0; --i)out<<x.num[i];        out<<x.num[0];    return out;}
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