) 的error及错误的指针

输入了书上练习题答案的代码：
#include <string>
#include <iostream>
using namespace std;
class screen{
public :
    typedef string ::size_type index;
    char get() const{   return contents[ cursor];}
    inline char get(index ht,index wd) const;
    index get_cursor() const;
    screen(index hght, index wdth,const  string & cntnts);
    screen& set (char);
    screen& move (index r,index c);
   
    screen& display(ostream & os);
private :
    string contents;
    index cursor;
    index height;
    index width;
};

screen ::screen(index hght, index wdth,const string &cntnts):
contents (cntnts),cursor(0),height(hght),width(wdth){}
char screen:: get (index r,index c)const
{
    index row=r*width;
    return contents[row+c];
}
inline screen::index screen ::get_cursor() const
{
    return cursor;
}
screen &screen ::set(char c)
{
    contents[cursor]=c;
    return *this;
}
screen &screen:: move(index r,index c)
{
    index row=r* width;
    cursor=row+c;
    return *this;
}
screen& screen::display(ostream &os)
{
    os<<contents;
    return *this;
}
int main(){
    int a,b,d,e;
    string c;
    cin>>a>>b>>d>>e>>c;     
    screen myscreen(a,b,c);
    myscreen.move(d,e).set('#').display(cout);
    return 0;
}
问题截图：见附件文档               谢谢