#include<string.h>
#include<iostream.h>
#include<conio.h>
#include<stdlib.h>
#include<windows.h>
#define NULL 0
class string
{
private:
    char *str;
    int size;
public:
    string();
    string(char *string);
    void set(char *string);
    string operator =(string obj);
    string operator +(string obj);
    string substring(); 
    //void strconcat(string string1,string string2);
    //string strsub(string substring,string string,int count1,int len);
    //string strcopy(string string1,string string2);
    char *getstr(){return str;}
    int getsize(){return size;}
    void display();
    ~string();
};
string::string()
{
    size=1;
    str=new char[size];
    if(str==NULL)
    {
        cout<<"分配错误."<<endl;
        exit(1);
    }
    str=NULL;
}
string::string(char *string)
{
    size=strlen(string)+1;
    str=new char[size];
    if(str==NULL)
    {
        cout<<"分配错误."<<endl;
        exit(1);
    }
    strcpy(str,string);
}
void string::set(char *string)
{
    size=strlen(string)+1;
    str=new char[size];
    if(str==NULL)
    {
        cout<<"分配错误."<<endl;
        exit(1);
    }
    strcpy(str,string);
    size=strlen(str);
}
string string::operator =(string obj)
{
    string temp;
    int len;
    len=strlen(obj.str)+1;
    temp.str=new char[len];
    temp.size=len;
    if(temp.str==NULL)
    {
        cout<<"分配错误."<<endl;
        exit(1);
    }
    strcpy(temp.str,obj.str);
    
return temp;
}
string string::operator +(string obj)
{
    string temp;
    int len;
    len=strlen(obj.str)+strlen(str)+1;
    temp.str=new char;
    if(temp.str==NULL)
    {
        cout<<"分配错误."<<endl;
        exit(1);
    }
    strcpy(temp.str,str);
    strcpy(temp.str,obj.str);
    return temp;
}
string::~string()
{
    delete[]str;
}
void string ::display()
{
    cout<<"字符串长度为"<<size-1<<endl;
    cout<<"字符串为"<<str<<endl;

}
void printmeau(void)
{
    int i;
    char *a[9]=
    {
        "◆◆◆◆◆◆欢迎使用串编译器◆◆◆",
        "●1 →串拷贝                                      ",
        "●2 →求子串                                      ",
        "●3 →连接字符串                                  ",
        "●4 →求串长度                                    ",
        "●5 →串比较                                      ",
        "●6 →清屏                                        ",
        "●q →退出系统                                    ",
        "◆◆◆◆◆◆◆◆◆◆◆◆◆◆◆◆◆",
    };
    for(i=0;i<9;i++)
    {
        
        cout<<a[i]<<endl;
    }
}

void main()
{
    string str1,str2,str;
    char *string1,*string2;
    int d;
    char order;
    printmeau();

    while(order!='q'&&order!='Q')
    {
        cout<<"输入指令:";
        cin>>order;
        switch(order)
        {
        case '1':
            cout<<"请你输入字符串1"<<endl;
            string1=new char;
            cin>>string1;
            str1.set(string1);
            cout<<"请你输入字符串2"<<endl;
            string2=new char;
            cin>>string2;
            str2.set(string2);
            cout<<"请问你要将第几个拷贝给你另外一个(1或者2)："<<endl;
            cin>>d;
            if(d==1)
                str2=str1;
            else if(d==2)
                str1=str2;
            else
            cout<<"输入有误。"<<endl;
            break;
        case '3':
            cout<<"请你输入字符串1"<<endl;
            string1=new char;
            cin>>string1;
            str1.set(string1);
            cout<<"请你输入字符串2"<<endl;
            string2=new char;
            cin>>string2;
            str2.set(string2);
            str=str1+str2;
            str.display();
        case '4':
            cout<<"请你输入字符串"<<endl;
            string1=new char;
            cin>>string1;
            str1.set(string1);
            cout<<"该串长为："<<str1.getsize()<<endl;
            break;
        case '6':
            system("cls");
            printmeau();
            break;
        default:
            cout<<"你的命令有误。请再次";
            break;
        }
    }



}