有符号大整数计算器

/*编译环境：VC++ 6.0*/

/*之前做的课程设计，文档在这：https://wenku.baidu.com/view/94d8767a1eb91a37f1115cb5.html*/

#include <iostream>
#include <string>
#include <conio.h>
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>

using namespace std;

class Operation
{
public:
    char Check_Oper(string &str,string &num_1,string &num_2);     //检测运算符
    string addition(string &num1,string &num2);                   //加法运算
    string subduction(string &num1,string &num2);                 //减法运算
    string multiplication(string &num1,string &num2);             //乘法运算
    string division(string &num1,string &num2);                   //除法运算
    string factorial(string &num);                                //阶乘运算
private:
    string Reverse_String(string &str);                           //反转字符串
    string SUB_ASC(string &str);                                  //字符串ASCII码减48位
    string ADD_ASC(string &str);                                  //字符串ASCII码加48位
    string GET_MAX(string &num1,string &num2);                    //获取两个数中的最大值
};

string Operation::addition(string &num1,string &num2)
{
    unsigned short a=0,b=0;
    string result;
    string num_1(num1);
    string num_2(num2);
    string::size_type i=0,j=0;
    Reverse_String(num_1);
    Reverse_String(num_2);
    SUB_ASC(num_1);
    SUB_ASC(num_2);
    for(i=0; i!=num_1.size(); i++) a+=num_1[i];
    for(j=0; j!=num_2.size(); j++) b+=num_2[j];
    if(a!=0 || b!=0) goto skip;
    result.insert(result.begin(),’0′);
    return result;
skip:
    i=j=0;
    while(i!=num_1.size() || j!=num_2.size())
    {
        if(i!=num_1.size() && j!=num_2.size()) result.insert(result.end(),num_1[i]+num_2[j]);
        else if(i!=num_1.size()) result.insert(result.end(),num_1[i]);
        else if(j!=num_2.size()) result.insert(result.end(),num_2[j]);
        i==num_1.size()?i:i++;
        j==num_2.size()?j:j++;

    }
    for(i=0; i!=result.size(); i++)
        if(result[i]>9)
        {
            result[i]%=10;
            if(i+1==result.size()) result.insert(result.end(),0);
            result[i+1]+=1;
        }
    ADD_ASC(result);
    Reverse_String(result);
    while(1)
    {
        if(*result.begin()==’0′) result.erase(result.begin());
        else break;
    }
    return result;
}

string Operation::subduction(string &num1,string &num2)
{
    short k=0;
    string result;
    string::size_type i=0,j=0;
    string num_1(num1);
    string num_2(num2);

    if(GET_MAX(num_1,num_2)==num_2)
    {
        k=1;
        num_2.swap(num_1);       //交换对象数据
    }
    Reverse_String(num_1);
    Reverse_String(num_2);
    SUB_ASC(num_1);
    SUB_ASC(num_2);
    i=j=0;
    while(i!=num_1.size() || j!=num_2.size())
    {
        if(i!=num_1.size() && j!=num_2.size()) result.insert(result.end(),num_1[i]-num_2[j]);
        else if(i!=num_1.size()) result.insert(result.end(),num_1[i]);
        else if(j!=num_2.size()) result.insert(result.end(),num_2[j]);
        i==num_1.size()?i:i++;
        j==num_2.size()?j:j++;

    }
    for(i=0; i!=result.size(); i++)
        if(result[i]<0)
        {
            result[i]=10+result[i];
            result[i+1]-=1;
        }
    ADD_ASC(result);
    Reverse_String(result);
    while(1)
    {
        if(*result.begin()==’0′) result.erase(result.begin());
        else break;
    }
    if(k)
    {
        if(result.empty())
            result.insert(result.end(),’0′);
        else
            result.insert(result.begin(),’-‘);
    }
    return result;
}

string Operation::multiplication(string &num1,string &num2)
{
    string result,temp;
    string num_1(num1);
    string num_2(num2);
    string::size_type i=0,j=0,m=0;
    short k=1;
    char tmp=NULL;
    Reverse_String(num_1);
    Reverse_String(num_2);
    SUB_ASC(num_1);
    SUB_ASC(num_2);
    for(i=0; i!=num_1.size(); i++) result.insert(result.end(),num_2[0]*num_1[i]);
    for(m=0; m!=result.size(); m++)
        if(result[m]>9)
        {
            tmp=result[m];
            result[m]%=10;
            if(m+1==result.size()) result.insert(result.end(),0);
            result[m+1]+=tmp/10;
        }
    while(j!=num_2.size()-1)
    {
        j++;
        if(j==num_2.size()) break;
        for(i=0; i!=num_1.size(); i++) temp.insert(temp.end(),num_2[j]*num_1[i]);
        temp.insert(temp.begin(),k,0);

        for(m=0; m<temp.size(); m++) temp[m]+=result[m];
        for(m=0; m<temp.size(); m++)
            if(temp[m]>9)
            {
                tmp=temp[m];
                temp[m]%=10;
                if(m+1==temp.size()) temp.insert(temp.end(),0);
                temp[m+1]+=tmp/10;
            }
        result.assign(temp);
        ADD_ASC(result);
        SUB_ASC(result);
        temp.erase(temp.begin(),temp.end());
        k++;
    }
    Reverse_String(result);
    ADD_ASC(result);
    return result;
}

string Operation::division(string &num1,string &num2)
{
    string result;
    string MAX;
    string remainder;
    string num1_tmp;
    string num_1(num1);
    string num_2(num2);
    string step(1,’1′);
    string temp1,temp2;
    string::iterator iter=NULL;
    string::size_type i=0;

    while(*num_2.begin()==’0′) num_2.erase(num_2.begin());
    if(num_2.empty())
    {
        result=”除数不可以为零!”;
        return result;
    }
    num_1.insert(num_1.end(),100,’0′);
    iter=num_1.begin()+num_2.size();
    num1_tmp.assign(num_1.begin(),iter);
    iter–;
again:
    for(step[0]=’1′; 1; step[0]++)
    {
        MAX.assign(GET_MAX(multiplication(num_2,step),num1_tmp));
        if(step[0]==’9′ && num1_tmp==MAX) goto skip;
        if(MAX!=num1_tmp)
        {
            step[0]–;
skip:
            temp2.assign(subduction(num1_tmp,multiplication(num_2,step)));
            while(1)
                if(temp2[0]==’0′) temp2.erase(temp2.begin());
                else break;
            result+=step;
            iter++;
            if(iter==num_1.end())
            {
                result.insert(result.begin(),num_2.size()-1,’0′);
                i=result.size()-100;
                result.insert(i,1,’.’);
                while(*result.begin()==’0′ && *(result.begin()+1)!=’.’)
                    result.erase(result.begin());
                while(*(result.end()-1)==’0′ && *(result.end()-2)!=’.’) result.erase(result.end()-1);
                break;
            }
            num1_tmp.assign(temp2);
            num1_tmp.insert(num1_tmp.end(),*iter);
            goto again;
        }
    }
    return result;
}

string Operation::factorial(string &num)
{
    string result(num);
    string step(1,’1′);
    string _num(num);
// if(num.size()<=1)
//   if(num[0]==’1′ || num[0]==’0′)
//    return step;
// cout <<num<<endl;
// result.assign(multiplication(factorial(subduction(num,step)),num));
    for(_num.assign(subduction(_num,step)); _num.size()==1?(_num[0]==’1′ || _num[0]==’0′?0:1):1; _num.assign(subduction(_num,step)))
        result.assign(multiplication(result,_num));
    return result;
}

char Operation::Check_Oper(string &str,string &num_1,string &num_2)
{
    char ch=NULL;
    short k=1;
    string::size_type i;
    if(str[str.size()-1]==’!’)
        if(str[0]>=48 && str[0]<=57)
            return ‘!’;
        else
            return NULL;
    if(str[0]!=’-‘) i=0;
    else if(str[0]==’-‘)
    {
        num_1.insert(num_1.end(),’-‘);
        i=1;
    }
    else if(str[0]==’+’) i=1;
    else return NULL;
    for(; i<str.size(); i++)
    {
        if(str[i]>=48 && str[i]<=57)
        {
            if(k) num_1.insert(num_1.end(),str[i]);
            else
                num_2.insert(num_2.end(),str[i]);
        }
        else
        {
            if(ch!=NULL) return NULL;
            switch(str[i])
            {
            case ‘+’:
                ch=’+’;
                break;
            case ‘-‘:
                ch=’-‘;
                break;
            case ‘*’:
                ch=’*’;
                break;
            case ‘/’:
                ch =’/’;
                break;
            default:
                return NULL;
            }
            k=0;
        }
    }
    return ch;
}

string Operation::Reverse_String(string &str)
{
    string::size_type i,j=str.size()-1,length=str.size()/2;
    char tmp=NULL;
    for(i=0; i<length; i++,j–)
    {
        tmp=str[i];
        str[i]=str[j];
        str[j]=tmp;
    }
    return str;
}

string Operation::SUB_ASC(string &str)
{
    string::size_type i;
    for(i=0; i<str.size(); i++) str[i]-=48;
    return str;
}

string Operation::ADD_ASC(string &str)
{
    string::size_type i;
    for(i=0; i<str.size(); i++) str[i]+=48;
    return str;
}

string Operation::GET_MAX(string &num1,string &num2)
{
    string num_1(num1);
    string num_2(num2);
    string::size_type i;

    while(num_1[0]==’0′ || num_2[0]==’0′)
    {
        if(num_1[0]==’0′) num_1.erase(num_1.begin());
        if(num_2[0]==’0′) num_2.erase(num_2.begin());
    }
    if(num_1.size()>num_2.size()) return num_1;
    else if(num_1.size()<num_2.size()) return num_2;
    else
    {
        for(i=0; i!=num_1.size(); i++)
            if(num_1[i]>num_2[i]) return num_1;
            else if(num_1[i]<num_2[i]) return num_2;
    }
    return num_1;
}

int Console()
{
    system(“cls”);
    SetConsoleTitle(“有符号大整型数字计算器 ——By:计科12-1班魏子楠”);
    cout <<“===============================================================================”<<endl;
    cout <<“\t\t\t有符号大整型数字计算器”<<endl;
    cout <<“本程序可进行:\n1.加法运算\t2.减法运算\t3.乘法运算\t4.除法运算\t5.阶乘运算”<<endl;
    cout <<“===============================================================================”<<endl;
    return 1;
}

int main(int argc,char *argv[])
{
char ch;
    Operation oper;
again:
    string *_str=new string;
    string *_num1=new string;
    string *_num2=new string;
    string *_result=new string;
    string &str=*_str;
    string &num1=*_num1;
    string &num2=*_num2;
    string &result=*_result;

    Console();
    fflush(stdin);
    cout <<“请输入运算式:”<<endl;
    cin >>str;
    if((ch=oper.Check_Oper(str,num1,num2))==NULL) cout <<“输入有误!”<<endl;
    if(num1[0]==’-‘)
        switch(ch)
        {
        case ‘+’:
            num1.erase(num1.begin());
            result.assign(oper.subduction(num2,num1));
            break;
        case ‘-‘:
            num1.erase(num1.begin());
            result.assign(oper.addition(num1,num2));
            result.insert(result.begin(),’-‘);
            break;
        case ‘*’:
            num1.erase(num1.begin());
            result.assign(oper.multiplication(num1,num2));
            result.insert(result.begin(),’-‘);
            break;
        case ‘/’:
            num1.erase(num1.begin());
            result.assign(oper.division(num1,num2));
            result.insert(result.begin(),’-‘);
            break;
        default:
            cout <<“数据出错!”<<endl;
            return -1;
        }
    else
        switch(ch)
        {
        case ‘+’:
            result.assign(oper.addition(num1,num2));
            break;
        case ‘-‘:
            result.assign(oper.subduction(num1,num2));
            break;
        case ‘*’:
            result.assign(oper.multiplication(num1,num2));
            break;
        case ‘/’:
            result.assign(oper.division(num1,num2));
            break;
        case ‘!’:
            str.erase(str.end()-1);
            result.assign(oper.factorial(str));
            break;
        default:
            cout <<“数据出错!”<<endl;
            return -1;
        }
    cout <<“计算结果:”<<endl<<result<<endl;