cpp primier plus homework c10

//c10_01
//header
#ifndef ACCOUNT_H_
#define ACCOUNT_H_
#include <string>
class Account
{
    //using std::string;
private:
    std::string m_username;//prefix  m_
    std::string m_accname;
    long double m_money;
public:
   // void init();
    void show_account()const;
    void deposit(long double m);
    void withdraw(long double n);
    Account();//default constructor
    Account(const std::string &username,const std::string &accname,long double money);//constructor
    ~Account();//destructor

};
#endif // ACCOUNT_H_
//memberfunc
 #include<iostream>
 #include"Account.h"
 #include<string>
 using std::cout;
 using std::endl;
 using std::string;
 //typename std::string string;
 void Account::show_account()const
 {
     cout<<"#Account owner:   "<<m_username<<endl;
     cout<<"#Account_name:   "<<m_accname<<endl;
     cout<<"#The money you have:   "<<m_money<<endl;
     cout<<"-------------------------------------"<<endl;
 }
void Account::deposit(long double m)
{
    m_money+=m;
}
void Account::withdraw(long double n)
{
    m_money-=n;
}
//Account()
Account::Account(const string &username,const string &accname,long double money)
{
    m_username=username;
    m_accname=accname;
    m_money=money;

}
Account::~Account()
{

}
//main
#include <iostream>
#include<string>
#include"Account.h"


int main(void)
{
    using namespace std;
    Account user1("w","Saury",100000);
    user1.show_account();
    user1.deposit(20000);
    user1.show_account();
    user1.withdraw(3000);
    user1.show_account();
}
//c10_o2
//header
#ifndef PERSON_H_
#define PERSON_H_
#include<string>
using std::string;
class Person
{
private:
    static const int LIMIT=25;
    string lname;
    char fname[LIMIT];
public:
    Person() {lname="";fname[0]='\0';}
    Person(const string &ln,const char*fn="Heyyou");
    void show() const;
    void FormalShow() const;
    ~Person();

};
#endif // PERSON_H_
//cpp
#include<iostream>
#include<string>
#include<cstring>
#include"Person.h"
using std::string;
using std::cout;
using std::endl;
Person::Person(const string &ln,const char*fn)
{
    lname=ln;
    strcpy(fname,fn);
}
//Person
void Person::show() const
{
   cout<<fname<<" "<<lname;
}
void Person::FormalShow() const
{
    cout<<lname<<" "<<fname;
}
Person::~Person()
{

}
//main
#include <iostream>
#include"Person.h"
#include<string>
using namespace std;

int main()
{
    Person one;
    Person two("Smythecraft");
    Person three("Dimwiddy","Sam");
    three.show();
    cout<<endl;
    three.FormalShow();
}