大整数四则运算

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// ////1. 输入形式为：A[空格或换行]O[空格或换行]B; //// 2. 1中A、B为大数，O为运算符（如输入：123456789 / 432432); //// 3. 既然处理大数，就没必要输入小数点位了; //// 4.加减不能处理负号，乘除可以; //// 5. 用于学习交流，若发现错误或不妥之处可联系 //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////// #include<iostream> #include<string> using namespace std; class BigFigure{ string num1,num2; string outcome; int precision; char operation; public: BigFigure(){ num1=num2="0"; outcome="0"; precision=5; } string& plus(string &, string &); string& subtration(string &, string &); string& multiplication(string &, string &); string& division(string &, string &); void show(); void BigFigureInterface(); string &revese(string&); friend istream& operator>>(istream& i, BigFigure& a){ return i>>a.num1>>a.operation>>a.num2; } ~BigFigure(){ } }; void BigFigure::show(){ cout<<"Result: "<<outcome<<endl; } void BigFigure::BigFigureInterface(){ BigFigure a; cout<<"*********************************************************/n"; cout<<" Welcome... /n"; cout<<" Four Arithmetic Operations of Big Figures/n"; cout<<"*********************************************************/n/n"; cout<<"Notes:/n"; cout<<" 1. 输入形式为：A[空格或换行]O[空格或换行]B。/n"; cout<<" 2. 1中A、B为大数，O为运算符（如输入：123456789 / 432432)。/n"; cout<<" 3. 既然处理大数，就没必要输入小数点位了。/n"; cout<<" 4. 加减不能处理负号，乘除可以。/n"; cout<<" 5. 用于学习交流，若发现错误可联系519916178@qq.com。/n/n"; cout<<"Now Start, Input 0 0 0 to end if you want to quit!/n/n"; cout<<"[BigFigure #] "; cin>>a; while(a.operation!='0'){ switch(a.operation){ case '+': a.plus(a.num1, a.num2); a.show(); break; case '-': a.subtration(a.num1, a.num2); a.show(); break; case '*': a.multiplication(a.num1, a.num2); a.show(); break; case '/': a.division(a.num1, a.num2); a.show(); break; default:cout<<a.operation<<" is not Arithmetic Operation./n"; } cout<<"[BigFigure #] "; cin>>a; } system("cls"); cout<<"/n/n/n/n/n/n/t/t Quited.../n/n/n/n/n/n/n"; system("pause"); } string& BigFigure::revese(string& s){ char c; int t=s.size(); for(int i=0; i<t/2; i++){ c=s[i]; s[i]=s[t-i-1]; s[t-i-1]=c; } return s; } string& BigFigure::plus(string &str1, string &str2){//加法运算，未处理符号 int min=0,i,t=0; string temp; outcome.clear(); str1=revese(str1); str2=revese(str2); min=str1.size()<str2.size() ? str1.size() : str2.size(); for(i=0; i<min; i++){ temp+=(str1[i]+str2[i]-96+t)%10+48; t=(str1[i]+str2[i]-96+t)/10; } if(min==str1.size()){ while(i<str2.size()){ temp+=(str2[i]+t-48)%10+48; t=(str2[i]-48+t)/10; i++; } if(t) temp+='1'; } else{ while(i<str1.size()){ temp+=(str1[i]+t-48)%10+48; t=(str1[i]-48+t)/10; i++; } if(t) temp+='1'; } outcome=revese(temp); return outcome; } string &BigFigure::subtration(string &str1, string &str2){//减法运算，未处理符号 int min=0,flag,i,t=0; string temp; outcome.clear(); if(str1.size()>str2.size() || (str1.size()==str2.size() && str1.compare(str2)==1)){ str1=revese(str1); str2=revese(str2); flag=0; min=str2.size(); } else if(str1.size()==str2.size()){ if(!str1.compare(str2)){ outcome='0'; return outcome; } if(str1.compare(str2)==-1){ temp=str1; str1=revese(str2); str2=revese(temp); flag=1; min=str2.size(); } } else{ temp=str1; str1=revese(str2); str2=revese(temp); flag=1; min=str2.size(); } temp.clear(); for(i=0; i<min; i++){ if(str1[i]-t<str2[i]){ temp+=str1[i]+10-t-str2[i]+48; t=1; } else{ temp+=str1[i]-t-str2[i]+48; t=0; } } while(i<str1.size()){ if(!t){ while(i<str1.size()){ temp+=str1[i]; i++; } break; } if(str1[i]!='0'){ temp+=str1[i]-t; t=0; } else temp+='9'; i++; } string s; for(unsigned int k=temp.size()-1; k>=0; k--){ if(temp[k]!='0'){ for(int n=k; n>=0; n--) s+=temp[n]; break; } } if(flag) s='-'+s; outcome=s; return outcome; } string& BigFigure::multiplication(string &str1, string &str2){//乘法运算，已处理符号 char c='0',flag=0; string temp1,temp2="0"; if(str1[0]=='0' || str2[0]=='0'){ outcome="0"; return outcome; } if(str1[0]=='-'){ flag++; str1.erase(0,1); } if(str2[0]=='-'){ flag++; str2.erase(0,1); } str1=revese(str1); str2=revese(str2); for(unsigned int i=0; i<str2.size(); i++){ c='0'; for(unsigned int j=0; j<str1.size(); j++){ temp1+=((str2[i]-48)*(str1[j]-48)+c-48)%10+48; c=((str2[i]-48)*(str1[j]-48)+c-48)/10+48; } if(c!='0') temp1+=c; temp1=revese(temp1); for(int k=0; k<i; k++) temp1+='0'; temp2=plus(temp1, temp2); temp1.clear(); } if(flag%2) temp2='-'+temp2; outcome=temp2; return outcome; } string& BigFigure::division(string &str1, string &str2){//除法运算，已处理符号 int str=0,flag=0,flag1=0,flag2=0; string temp,temps,tempt; if(str2=="0"){ outcome="Inf"; return outcome; } if(str2=="1" || str1=="0"){ outcome=str1; return outcome; } if(str1[0]=='-'){ flag++; str1.erase(0,1); } if(str2[0]=='-'){ flag++; str2.erase(0,1); } for(unsigned int i=0; i<str1.size(); i++){//整除处理 str=0; temp+=str1[i]; if(temp[0]=='0') temp.erase(0,1); if(temp.size()>str2.size() || (temp.size()==str2.size() && temp.compare(str2)>=0)){ while(temp.size()>str2.size() || (temp.size()==str2.size() && temp.compare(str2)>=0)){ tempt=str2; temp=subtration(temp, tempt); str++; } temps+=str+48; } else if(temp.size()==str2.size() && temp.compare(str2)==0) temps+='1'; else temps+='0'; } flag1=temps.size(); if(temp!="0" && precision) temps+='.'; for(int i=0; i<=precision && temp!="0"; i++){//小数后位的处理 str=0; temp+='0'; if(temp.size()>str2.size() || (temp.size()==str2.size() && temp.compare(str2)>=0)){ while(temp.size()>str2.size() || (temp.size()==str2.size() &&temp.compare(str2)>=0)){ tempt=str2; temp=subtration(temp, tempt); str++; } temps+=str+48; } else if(temp.size()==str2.size() && temp.compare(str2)==0) temps+='1'; else temps+='0'; } flag2=temps.size()-2; if(temps[temps.size()-1]>='5' && flag2-flag1==precision){//四舍五入处理 temps.erase(flag1,1); temps.erase(temps.size()-1, 1); temp="1"; temps=plus(temps, temp); if(temps.size()>flag2) temps.insert(flag1+1, 1, '.'); else temps.insert(flag1, 1, '.'); } else if(flag2-flag1==precision) temps.erase(temps.size()-1, 1); temp.clear(); for(unsigned int k=0; k<temps.size(); k++){//左端去零处理 if(temps[k]!='0' || temps[k+1]=='.'){ for(int n=k; n<temps.size(); n++) temp+=temps[n]; break; } } if(flag%2) temp='-'+temp; outcome=temp; return outcome; } int main(){//主函数 BigFigure a; a.BigFigureInterface(); return 0; }