實驗5 繼承和多型

實驗任務3：

pets.hpp

#pragma once

#include<iostream>
#include<string>

using std::string;
using std::cin;
using std::cout;
using std::endl;


class MachinePets
{
public:
    MachinePets(const string& s);
    virtual string talk() = 0;
    string get_nickname()const;
private:
    string nickname;
};

MachinePets::MachinePets(const string& s):nickname{s}{}

string MachinePets::get_nickname()const
{
    return nickname;
}

class PetCats :public MachinePets
{
public:
    PetCats(const string& s);
    string talk() override;
private:

};

PetCats::PetCats(const string& s):MachinePets{s}{}

string PetCats::talk()
{
    return string("miao~ miao~ ");
}

class PetDogs :public MachinePets
{
public:
    PetDogs(const string& s);
    string talk() override;
private:

};
PetDogs::PetDogs(const string& s):MachinePets{s}{}

string PetDogs::talk()
{
    return string("wang! wang!");
}

task3.cpp

#include <iostream>
#include <vector>
#include "pets.hpp"

void test() {
    using namespace std;

    vector<MachinePets*> pets;

    pets.push_back(new PetCats("miku"));
    pets.push_back(new PetDogs("da huang"));

    for (auto& ptr : pets)
        cout << ptr->get_nickname() << " says " << ptr->talk() << endl;
}

int main() {
    test();
}

實驗任務4：

film.hpp

#pragma once
#include<iostream>
#include<string>
#include<iomanip>
using std::cin;
using std::cout;
using std::string;
using std::istream;
using std::ostream;
using std::setw;
using std::left;

class Film
{
public:
    Film(){}
    friend istream& operator>>(istream& in,Film& f);
    friend ostream& operator<<(ostream& out,const Film& f);
    friend bool compare_by_year(const Film& f1, const Film& f2);
private:
    string film_name;
    string director_name;
    string film_area;
    int year;
};

istream& operator>>(istream& in, Film& f)
{
    cout << "錄入片名："; in >> f.film_name;
    cout << "錄入導演："; in >> f.director_name;
    cout << "錄入製片國家/地區："; in >> f.film_area;
    cout << "錄入上映年份："; in >> f.year;
    return in;
}

ostream& operator<<(ostream& out, const Film& f)
{
    out << left;
    out << setw(15) << f.film_name
        << setw(15) << f.director_name
        << setw(15) << f.film_area
        << setw(15) << f.year;
    return out;
}

bool compare_by_year(const Film& f1, const Film& f2)
{
    return f1.year < f2.year;
}

task4.cpp

#include "film.hpp"
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

void test() {
    using namespace std;

    int n;
    cout << "輸入電影數目: ";
    cin >> n;

    cout << "錄入" << n << "部影片資訊" << endl;
    vector<Film> film_lst;
    for (int i = 0; i < n; ++i) {
        Film f;
        cout << string(20, '-') << "第" << i + 1 << "部影片錄入" << string(20, '-') << endl;
        cin >> f;
        film_lst.push_back(f);
    }

    // 按發行年份升序排序
    sort(film_lst.begin(), film_lst.end(), compare_by_year);

    cout << string(20, '=') + "電影資訊(按發行年份)" + string(20, '=') << endl;
    for (auto& f : film_lst)
        cout << f << endl;
}

int main() {
    test();
}

實驗任務5：

Complex.hpp

#include<iostream>
#include<cmath>
using std::istream;
using std::ostream;

template <typename T>
class Complex
{
public:
    Complex(T r=0,T i=0):real{r},imag{i}{}
    Complex(const Complex<T>& c) { real = c.real, imag = c.imag; }

    T get_real()const { return real; }
    T get_imag()const { return imag; }

    bool operator== (const Complex<T>&c);
    Complex<T> operator+=(const Complex<T>& c);

    template<typename U>
    friend Complex<U> operator+(const Complex<U>& c1, const Complex<U>& c2);

    template<typename U>
    friend istream& operator>>(istream& in, Complex<U>& c);
    template<typename U>
    friend ostream& operator<<(ostream& out, const Complex<U>& c);

private:
    T real;
    T imag;
};
template<typename T>
bool Complex<T>::operator==(const Complex<T>& c)
{
    return real == c.real && imag == c.imag;
}

template<typename T>
Complex<T> Complex<T>::operator+=(const Complex<T>& c)
{
    real += c.real;
    imag += c.imag;
    return *this;
}

template<typename T>
Complex<T> operator+(const Complex<T>& c1, const Complex<T>& c2)
{
    return Complex<T>(c1.real + c2.real, c1.imag + c2.imag);
}

template<typename T>
istream& operator>>(istream& in, Complex<T>& c)
{
    in >> c.real >> c.imag;
    return in;
}

template<typename T>
ostream& operator<<(ostream& out, const Complex<T>& c)
{
    if (c.imag >= 0) { out << c.real << " + " << abs(c.imag) << "i"; }
    else { out << c.real << " - " << abs(c.imag) << "i"; }
    return out;
}

task5.cpp

#include "Complex.hpp"
#include <iostream>

using std::cin;
using std::cout;
using std::endl;
using std::boolalpha;

void test1() {
    Complex<int> c1(2, -5), c2(c1);

    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;
    cout << "c1 + c2 = " << c1 + c2 << endl;

    c1 += c2;
    cout << "c1 = " << c1 << endl;
    cout << boolalpha << (c1 == c2) << endl;
}

void test2() {
    Complex<double> c1, c2;
    cout << "Enter c1 and c2: ";
    cin >> c1 >> c2;
    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;

    cout << "c1.real = " << c1.get_real() << endl;
    cout << "c1.imag = " << c1.get_imag() << endl;
}

int main() {
    cout << "自定義類别範本Complex測試1: " << endl;
    test1();

    cout << endl;

    cout << "自定義類别範本Complex測試2: " << endl;
    test2();
}

實驗任務6：

date.h

//date.h
#ifndef _DATE_H_
#define _DATE_H_
class Date
{
private:
        int year;
        int month;
        int day;
        int totalDays;
public:
    Date(int year,int month,int day);
    int getYear()const{return year;}
    int getMonth()const{return month;}
    int getDay()const {return day;}
    int getMaxDay()const;
    bool isLeapYear()const
    {
        return year%4==0&&year%100!=0||year%400==0;
    }
    void show()const;
    int operator-(const Date&date)const
    {
        return totalDays-date.totalDays;
    }
 };
 
 #endif//_DATE_H_ 

date.cpp

#include"date.h"
#include<iostream>
#include<cstdlib>
using namespace std;
namespace
{
    const int DAYS_BEFORE_MONTH[]={0,31,59,90,120,151,181,212,243,273,304,334,365};
}

Date::Date(int year,int month,int day):year{year},month{month},day{day}
{
    if(day<=0||day>getMaxDay())
    {
        cout<<"Invalid date:";
        show();
        cout<<endl;
        exit(1);
    }
    int years=year-1;
    totalDays=years*365+years/4-years/100+years/400+DAYS_BEFORE_MONTH[month-1]+day;
    if(isLeapYear()&&month>2)totalDays++; 
}

int Date::getMaxDay()const
{
    if(isLeapYear()&&month==2){return 29;
    }
    else{return DAYS_BEFORE_MONTH[month]-DAYS_BEFORE_MONTH[month-1];
    }
}

void Date::show()const
{
    cout<<getYear()<<"-"<<getMonth()<<"-"<<getDay();
}

accumulator.h

//accumulator.h
#ifndef _ACCUMULATOR_H_
#define _ACCUMULATOR_H_
#include "date.h"

class Accumulator {
    //將某個數值按日累加
private:
    Date lastDate;     //上次變更數值的時期
    double value;      //數值的當前值
    double sum;        //數值按日累加之和
public:
    //建構函式,date為開始累加的日期,value為初始值
    Accumulator(const Date &date, double value)
        : lastDate(date), value(value), sum(0) {}
    //獲得日期date的累加結果
    double getSum(const Date &date) const {
        return sum + value * (date-lastDate);
    }
    //在date將數值變更為value
    void change(const Date &date, double value) {
        sum = getSum(date);
        lastDate = date;
        this->value = value;
    }
    //初始化,將日期變為date,數值變為value,累加器清零
    void reset(const Date &date, double value) {
        lastDate = date;
        this->value = value;
        sum = 0;
    }
};
#endif //_ACCUMULATOR_H_

account.h

//accouth.h
#ifndef _ACCOUNT_H_
#define _ACCOUNT_H_
#include "date.h"
#include "accumulator.h"
#include <string>

class Account {
private:
    std::string id;
    double balance;
    static double total;
protected:
    // 建構函式
    Account(const Date& date, const std::string& id);
    void record(const Date& date, double amount, const std::string& desc);
    // 報告錯誤資訊
    void error(const std::string& msg) const;
public:
    // 獲取賬戶ID
    const std::string& getId() const;
    // 獲取賬戶餘額
    double getBalance() const;
    // 獲取所有賬戶的總金額
    static double getTotal();
    // 存入現金，date為日期，amount為金額，desc為款項說明
    virtual void deposit(const Date& date, double amount, const std::string& desc)=0;
    // 取出現金，date為日期，amount為金額，desc為款項說明
    virtual void withdraw(const Date& date, double amount, const std::string& desc)=0;
    // 結算（計算利息、年費等），每月結算一次，date為結算日期
    virtual void settle(const Date& date)=0;
    // 顯示賬戶資訊
    virtual void show() const;
};
class SavingsAccount:public Account
{
private:
    Accumulator acc;        //輔助計算利息的累加器
    double rate;            //存款的年利率
public:
    //建構函式
    SavingsAccount(const Date &date, const std::string &id, double rate);
    double getRate() const { return rate; }
    //存入現金
    void deposit(const Date &date, double amount, const std::string &desc);
    //取出現金
    void withdraw(const Date &date, double amount, const std::string &desc);
    //結算利息,每年1月1日呼叫一次該函式
    void settle(const Date &date);
};

class CreditAccount : public Account {    //信用賬戶類
private:
    Accumulator acc;        //輔助計算利息的累加器
    double credit;          //信用額度
    double rate;            //欠款的日利率
    double fee;             //信用卡年費
    double getDebt() const {
        double balance = getBalance();
        return (balance < 0? balance : 0);
    }
public:
    //建構函式
    CreditAccount(const Date &date, const std::string &id, double credit, double rate, double fee);
    double getCredit() const { return credit; }
    double getRate() const { return rate; }
    double getFee() const { return fee; }
    double getAvailableCredit() const {
    if (getBalance() < 0)
        return credit + getBalance();
    else
        return credit;
    }
    //存入現金
    void deposit(const Date &date, double amount, const std::string &desc);
    //取出現金
    void withdraw(const Date &date, double amount, const std::string &desc);
    void settle(const Date &date);
    //顯示賬戶資訊
    void show() const;
};
#endif

account.cpp

//account.cpp
#include "account.h"
#include <cmath>
#include <iostream>
using namespace std;

double Account::total = 0;

//Account類的實現
Account::Account(const Date &date, const string &id)
    : id(id), balance(0) {
    date.show();
    cout << "\t#" << id << " created" << endl;
}

void Account::record(const Date &date, double amount, const string &desc) {
    amount = floor(amount * 100 + 0.5) / 100; //保留小數點後兩位
    balance += amount;
    total += amount;
    date.show();
    cout << "\t#" << id << "\t" << amount << "\t" << balance << "\t" << desc << endl;
}

void Account::show() const {
    cout << id << "\tBalance: " << balance;
}

void Account::error(const string &msg) const {
    cout << "Error(#" << id << "): " << msg << endl;
}

double Account::getBalance()const
{
    return balance;
}

double Account::getTotal()
{
    return total;
}

//SavingsAccount類相關成員函式的實現
SavingsAccount::SavingsAccount(const Date &date, const string &id, double rate)
    : Account(date, id), rate(rate), acc(date, 0) {}

void SavingsAccount::deposit(const Date &date, double amount, const string &desc) {
    record(date, amount, desc);
    acc.change(date, getBalance());
}
void SavingsAccount::withdraw(const Date &date, double amount, const string &desc) {
    if (amount > getBalance()) {
        error("not enough money");
    } else {
        record(date, -amount, desc);
        acc.change(date, getBalance());
    }
}

void SavingsAccount::settle(const Date &date) {
    if(date.getMonth()==1)
    {
        double interest=acc.getSum(date)*rate/(date-Date(date.getYear()-1,1,1));
        if(interest!=0)
        {
            record(date,interest,"interest");
        }
        acc.reset(date,getBalance());
    }
}

//CreditAccount類相關成員函式的實現
CreditAccount::CreditAccount(const Date &date, const string &id, double credit, double rate, double fee)
    : Account(date, id), credit(credit), rate(rate), fee(fee), acc(date, 0) {}

void CreditAccount::deposit(const Date &date, double amount, const string &desc) {
    record(date, amount, desc);
    acc.change(date, getDebt());
}

void CreditAccount::withdraw(const Date &date, double amount, const string &desc) {
    if (amount - getBalance() > credit) {
        error("not enough credit");
    } else {
        record(date, -amount, desc);
        acc.change(date, getDebt());
    }
}

void CreditAccount::settle(const Date &date) {
    double interest = acc.getSum(date) * rate;
    if (interest!= 0)
        record(date, interest, "interest");
    if (date.getMonth() == 1)
        record(date, -fee, "annual fee");
    acc.reset(date, getDebt());
}

void CreditAccount::show() const {
    Account::show();
    cout << "\tAvailable credit: " << getAvailableCredit();
}

8_8.cpp

// 8_8.cpp
#include "account.h"
#include <iostream>
using namespace std;

int main() {
    Date date(2008, 11, 1); // 起始日期

    // 建立幾個賬戶
    SavingsAccount sa1(date, "S3755217", 0.015);
    SavingsAccount sa2(date, "02342342", 0.015);
    CreditAccount ca(date, "C5392394", 10000, 0.0005, 50);
    Account *accounts[] = {&sa1, &sa2, &ca};

    const int n = sizeof(accounts) / sizeof(Account *);

    cout << "(d)deposit (w)withdraw (s)show (c)change day (n)next month (e)exit" << endl;

    char cmd;
    do {
        // 顯示日期和總金額
        date.show();
        cout << "\tTotal: " << Account::getTotal() << "\tcommand>";

        int index, day;
        double amount;
        string desc;
        cin >> cmd;

        switch (cmd) {
        case 'd': // 存入現金
            cin >> index >> amount;
            getline(cin, desc);
            accounts[index]->deposit(date, amount, desc);
            break;
        case 'w': // 取出現金
            cin >> index >> amount;
            getline(cin, desc);
            accounts[index]->withdraw(date, amount, desc);
            break;
        case 's': // 查詢各賬戶資訊
            for (int i = 0; i < n; i++) {
                cout << "[" << i << "] ";
                accounts[i]->show();
                cout << endl;
            }
            break;
        case 'c': // 改變日期
            cin >> day;
            if (day < date.getDay())
                cout << "You cannot specify a previous day";
            else if (day > date.getMaxDay())
                cout << "Invalid day";
            else
                date = Date(date.getYear(), date.getMonth(), day);
            break;
        case 'n': // 進入下個月
            if (date.getMonth() == 12)
                date = Date(date.getYear() + 1, 1, 1);
            else
                date = Date(date.getYear(), date.getMonth() + 1, 1);
            for (int i = 0; i < n; i++)
                accounts[i]->settle(date);
            break;
        }
    } while (cmd!= 'e');

    return 0;
}

實驗任務7：

container.h

//=======================
//        container.h
//=======================

// The so-called inventory of a player in RPG games
// contains two items, heal and magic water

#ifndef _CONTAINER_H_ // Conditional compilation
#define _CONTAINER_H_

class container // Inventory
{
protected:
    int numOfHeal; // number of heal
    int numOfMW;   // number of magic water
public:
    container();                    // constuctor
    void set(int heal_n, int mw_n); // set the items numbers
    int nOfHeal();                    // get the number of heal
    int nOfMW();                    // get the number of magic water
    void display();                    // display the items;
    bool useHeal();                    // use heal
    bool useMW();                    // use magic water
};

#endif

container.cpp

//=======================
//        container.cpp
//=======================
#include"container.h"
#include<iostream>
using std::cout;
using std::endl;
// default constructor initialise the inventory as empty
container::container()
{
    set(0, 0);
}

// set the item numbers
void container::set(int heal_n, int mw_n)
{
    numOfHeal = heal_n;
    numOfMW = mw_n;
}

// get the number of heal
int container::nOfHeal()
{
    return numOfHeal;
}

// get the number of magic water
int container::nOfMW()
{
    return numOfMW;
}

// display the items;
void container::display()
{
    cout << "Your bag contains: " << endl;
    cout << "Heal(HP+100): " << numOfHeal << endl;
    cout << "Magic Water (MP+80): " << numOfMW << endl;
}

// use heal
bool container::useHeal()
{
    numOfHeal--;
    return 1; // use heal successfully
}

// use magic water
bool container::useMW()
{
    numOfMW--;
    return 1; // use magic water successfully
}

player.h

//=======================
//        player.h
//=======================
#include<string>
using std::string;
// The base class of player
// including the general properties and methods related to a character

#ifndef _PLAYER
#define _PLAYER

#include <iomanip> // use for setting field width
#include <time.h>  // use for generating random factor
#include "container.h"

enum job
{
    sw,
    ar,
    mg
}; /* define 3 jobs by enumerate type
          sword man, archer, mage */
class player
{
    friend void showinfo(player &p1, player &p2);
    friend class swordsman;

protected:
    int HP, HPmax, MP, MPmax, AP, DP, speed, EXP, LV;
    // General properties of all characters
    string name;   // character name
    job role;       /* character's job, one of swordman, archer and mage,
                      as defined by the enumerate type */
    container bag; // character's inventory

public:
    virtual bool attack(player &p) = 0;        // normal attack
    virtual bool specialatt(player &p) = 0; // special attack
    virtual void isLevelUp() = 0;            // level up judgement
    /* Attention!
    These three methods are called "Pure virtual functions".
    They have only declaration, but no definition.
    The class with pure virtual functions are called "Abstract class", which can only be used to inherited, but not to constructor objects.
    The detailed definition of these pure virtual functions will be given in subclasses. */

    void reFill();              // character's HP and MP resume
    bool death();              // report whether character is dead
    void isDead();              // check whether character is dead
    bool useHeal();              // consume heal, irrelevant to job
    bool useMW();              // consume magic water, irrelevant to job
    void transfer(player &p); // possess opponent's items after victory
    void showRole();          // display character's job

private:
    bool playerdeath; // whether character is dead, doesn't need to be accessed or inherited
};

#endif

player.cpp

//=======================
//        player.cpp
//=======================
#include"player.h"
#include<iostream>
#include<iomanip>
using std::setw;
using std::cout;
using std::endl;
// character's HP and MP resume
void player::reFill()
{
    HP = HPmax; // HP and MP fully recovered
    MP = MPmax;
}

// report whether character is dead
bool player::death()
{
    return playerdeath;
}

// check whether character is dead
void player::isDead()
{
    if (HP <= 0) // HP less than 0, character is dead
    {
        cout << name << " is Dead." << endl;
        system("pause");
        playerdeath = 1; // give the label of death value 1
    }
}

// consume heal, irrelevant to job
bool player::useHeal()
{
    if (bag.nOfHeal() > 0)
    {
        HP = HP + 100;
        if (HP > HPmax) // HP cannot be larger than maximum value
            HP = HPmax; // so assign it to HPmax, if necessary
        cout << name << " used Heal, HP increased by 100." << endl;
        bag.useHeal(); // use heal
        system("pause");
        return 1; // usage of heal succeed
    }
    else // If no more heal in bag, cannot use
    {
        cout << "Sorry, you don't have heal to use." << endl;
        system("pause");
        return 0; // usage of heal failed
    }
}

// consume magic water, irrelevant to job
bool player::useMW()
{
    if (bag.nOfMW() > 0)
    {
        MP = MP + 100;
        if (MP > MPmax)
            MP = MPmax;
        cout << name << " used Magic Water, MP increased by 100." << endl;
        bag.useMW();
        system("pause");
        return 1; // usage of magic water succeed
    }
    else
    {
        cout << "Sorry, you don't have magic water to use." << endl;
        system("pause");
        return 0; // usage of magic water failed
    }
}

// possess opponent's items after victory
void player::transfer(player &p)
{
    cout << name << " got" << p.bag.nOfHeal() << " Heal, and " << p.bag.nOfMW() << " Magic Water." << endl;
    system("pause");
    // set the character's bag, get opponent's items
    bag.set(bag.nOfHeal() + p.bag.nOfHeal(), bag.nOfMW() + p.bag.nOfMW());
    
}

// display character's job
void player::showRole()
{
    switch (role)
    {
    case sw:
        cout << "Swordsman";
        break;
    case ar:
        cout << "Archer";
        break;
    case mg:
        cout << "Mage";
        break;
    default:
        break;
    }
}

// display character's job
void showinfo(player& p1, player& p2)
{
    system("cls");
    cout << "##############################################################" << endl;
    cout << "# Player" << setw(10) << p1.name << "   LV. " << setw(3) << p1.LV
         << "  # Opponent" << setw(10) << p2.name << "   LV. " << setw(3) << p2.LV << " #" << endl;
    cout << "# HP " << setw(3) << (p1.HP <= 999 ? p1.HP : 999) << '/' << setw(3) << (p1.HPmax <= 999 ? p1.HPmax : 999)
         << " | MP " << setw(3) << (p1.MP <= 999 ? p1.MP : 999) << '/' << setw(3) << (p1.MPmax <= 999 ? p1.MPmax : 999)
         << "     # HP " << setw(3) << (p2.HP <= 999 ? p2.HP : 999) << '/' << setw(3) << (p2.HPmax <= 999 ? p2.HPmax : 999)
         << " | MP " << setw(3) << (p2.MP <= 999 ? p2.MP : 999) << '/' << setw(3) << (p2.MPmax <= 999 ? p2.MPmax : 999) << "      #" << endl;
    cout << "# AP " << setw(3) << (p1.AP <= 999 ? p1.AP : 999)
         << " | DP " << setw(3) << (p1.DP <= 999 ? p1.DP : 999)
         << " | speed " << setw(3) << (p1.speed <= 999 ? p1.speed : 999)
         << " # AP " << setw(3) << (p2.AP <= 999 ? p2.AP : 999)
         << " | DP " << setw(3) << (p2.DP <= 999 ? p2.DP : 999)
         << " | speed " << setw(3) << (p2.speed <= 999 ? p2.speed : 999) << "  #" << endl;
    cout << "# EXP" << setw(7) << p1.EXP << " Job: " << setw(7);
    p1.showRole();
    cout << "   # EXP" << setw(7) << p2.EXP << " Job: " << setw(7);
    p2.showRole();
    cout << "    #" << endl;
    cout << "--------------------------------------------------------------" << endl;
    p1.bag.display();
    cout << "##############################################################" << endl;
}

swordsman.h

//=======================
//        swordsman.h
//=======================

// Derived from base class player
// For the job Swordsman

#include "player.h"
class swordsman : public player// subclass swordsman publicly inherited from base player
{
public:
    swordsman(int lv_in = 1, string name_in = "Not Given");
    // constructor with default level of 1 and name of "Not given"
    void isLevelUp();
    bool attack(player &p);
    bool specialatt(player &p);
    /* These three are derived from the pure virtual functions of base class
       The definition of them will be given in this subclass. */
    void AI(player &p); // Computer opponent
};

swordsman.cpp

//=======================
//        swordsman.cpp
//=======================
#include"swordsman.h"
#include<iostream>
#include<string>
using std::string;
using std::cout;
using std::endl;
// constructor. default values don't need to be repeated here
swordsman::swordsman(int lv_in, string name_in)
{
    role = sw; // enumerate type of job
    LV = lv_in;
    name = name_in;

    // Initialising the character's properties, based on his level
    HPmax = 150 + 8 * (LV - 1); // HP increases 8 point2 per level
    HP = HPmax;
    MPmax = 75 + 2 * (LV - 1); // MP increases 2 points per level
    MP = MPmax;
    AP = 25 + 4 * (LV - 1);       // AP increases 4 points per level
    DP = 25 + 4 * (LV - 1);       // DP increases 4 points per level
    speed = 25 + 2 * (LV - 1); // speed increases 2 points per level

    playerdeath = 0;
    EXP = LV * LV * 75;
    bag.set(lv_in, lv_in);
}

void swordsman::isLevelUp()
{
    if (EXP >= LV * LV * 75)
    {
        LV++;
        AP += 4;
        DP += 4;
        HPmax += 8;
        MPmax += 2;
        speed += 2;
        cout << name << " Level UP!" << endl;
        cout << "HP improved 8 points to " << HPmax << endl;
        cout << "MP improved 2 points to " << MPmax << endl;
        cout << "Speed improved 2 points to " << speed << endl;
        cout << "AP improved 4 points to " << AP << endl;
        cout << "DP improved 5 points to " << DP << endl;
        system("pause");
        isLevelUp(); // recursively call this function, so the character can level up multiple times if got enough exp
    }
}

bool swordsman::attack(player &p)
{
    double HPtemp = 0;             // opponent's HP decrement
    double EXPtemp = 0;             // player obtained exp
    double hit = 1;                 // attach factor, probably give critical attack
    srand((unsigned)time(NULL)); // generating random seed based on system time

    // If speed greater than opponent, you have some possibility to do double attack
    if ((speed > p.speed) && (rand() % 100 < (speed - p.speed))) // rand()%100 means generates a number no greater than 100
    {
        HPtemp = (int)((1.0 * AP / p.DP) * AP * 5 / (rand() % 4 + 10)); // opponent's HP decrement calculated based their AP/DP, and uncertain chance
        cout << name << "'s quick strike hit " << p.name << ", " << p.name << "'s HP decreased " << HPtemp << endl;
        p.HP = int(p.HP - HPtemp);
        EXPtemp = (int)(HPtemp * 1.2);
    }

    // If speed smaller than opponent, the opponent has possibility to evade
    if ((speed < p.speed) && (rand() % 50 < 1))
    {
        cout << name << "'s attack has been evaded by " << p.name << endl;
        system("pause");
        return 1;
    }

    // 10% chance give critical attack
    if (rand() % 100 <= 10)
    {
        hit = 1.5;
        cout << "Critical attack: ";
    }

    // Normal attack
    HPtemp = (int)((1.0 * AP / p.DP) * AP * 5 / (rand() % 4 + 10));
    cout << name << " uses bash, " << p.name << "'s HP decreases " << HPtemp << endl;
    EXPtemp = (int)(EXPtemp + HPtemp * 1.2);
    p.HP = (int)(p.HP - HPtemp);
    cout << name << " obtained " << EXPtemp << " experience." << endl;
    EXP = (int)(EXP + EXPtemp);
    system("pause");
    return 1; // Attack success
}

bool swordsman::specialatt(player &p)
{
    if (MP < 40)
    {
        cout << "You don't have enough magic points!" << endl;
        system("pause");
        return 0; // Attack failed
    }
    else
    {
        MP -= 40; // consume 40 MP to do special attack

        // 10% chance opponent evades
        if (rand() % 100 <= 10)
        {
            cout << name << "'s leap attack has been evaded by " << p.name << endl;
            system("pause");
            return 1;
        }

        double HPtemp = 0;
        double EXPtemp = 0;
        // double hit=1;
        // srand(time(NULL));
        HPtemp = (int)(AP * 1.2 + 20); // not related to opponent's DP
        EXPtemp = (int)(HPtemp * 1.5); // special attack provides more experience
        cout << name << " uses leap attack, " << p.name << "'s HP decreases " << HPtemp << endl;
        cout << name << " obtained " << EXPtemp << " experience." << endl;
        p.HP = (int)(p.HP - HPtemp);
        EXP = (int)(EXP + EXPtemp);
        system("pause");
    }
    return 1; // special attack succeed
}

// Computer opponent
void swordsman::AI(player &p)
{
    if ((HP < (int)((1.0 * p.AP / DP) * p.AP * 1.5)) && (HP + 100 <= 1.1 * HPmax) && (bag.nOfHeal() > 0) && (HP > (int)((1.0 * p.AP / DP) * p.AP * 0.5)))
    // AI's HP cannot sustain 3 rounds && not too lavish && still has heal && won't be killed in next round
    {
        useHeal();
    }
    else
    {
        if (MP >= 40 && HP > 0.5 * HPmax && rand() % 100 <= 30)
        // AI has enough MP, it has 30% to make special attack
        {
            specialatt(p);
            p.isDead(); // check whether player is dead
        }
        else
        {
            if (MP < 40 && HP > 0.5 * HPmax && bag.nOfMW())
            // Not enough MP && HP is safe && still has magic water
            {
                useMW();
            }
            else
            {
                attack(p); // normal attack
                p.isDead();
            }
        }
    }
}

main.cpp

//=======================
//        main.cpp
//=======================

// main function for the RPG style game

#include <iostream>
#include <string>
using namespace std;

#include "swordsman.h"
#include"player.h"

int main()
{
    string tempName;
    bool success = 0; // flag for storing whether operation is successful
    cout << "Please input player's name: ";
    cin >> tempName; // get player's name from keyboard input
    player *human=nullptr;     // use pointer of base class, convenience for polymorphism
    int tempJob;     // temp choice for job selection
    do
    {
        cout << "Please choose a job: 1 Swordsman, 2 Archer, 3 Mage" << endl;
        cin >> tempJob;
        system("cls"); // clear the screen
        switch (tempJob)
        {
        case 1:
            human = new swordsman(1, tempName); // create the character with user inputted name and job
            success = 1;                        // operation succeed
            break;
        default:
            break; // In this case, success=0, character creation failed
        }
    } while (success != 1); // so the loop will ask user to re-create a character

    int tempCom;                      // temp command inputted by user
    int nOpp = 0;                      // the Nth opponent
    for (int i = 1; nOpp < 5; i += 2) // i is opponent's level
    {
        nOpp++;
        system("cls");
        cout << "STAGE" << nOpp << endl;
        cout << "Your opponent, a Level " << i << " Swordsman." << endl;
        system("pause");
        swordsman enemy(i, "Warrior"); // Initialise an opponent, level i, name "Junior"
        human->reFill();               // get HP/MP refill before start fight

        while (!human->death() && !enemy.death()) // no died
        {
            success = 0;
            while (success != 1)
            {
                showinfo(*human, enemy); // show fighter's information
                cout << "Please give command: " << endl;
                cout << "1 Attack; 2 Special Attack; 3 Use Heal; 4 Use Magic Water; 0 Exit Game" << endl;
                cin >> tempCom;
                switch (tempCom)
                {
                case 0:
                    cout << "Are you sure to exit? Y/N" << endl;
                    char temp;
                    cin >> temp;
                    if (temp == 'Y' || temp == 'y')
                        return 0;
                    else
                        break;
                case 1:
                    success = human->attack(enemy);
                    human->isLevelUp();
                    enemy.isDead();
                    break;
                case 2:
                    success = human->specialatt(enemy);
                    human->isLevelUp();
                    enemy.isDead();
                    break;
                case 3:
                    success = human->useHeal();
                    break;
                case 4:
                    success = human->useMW();
                    break;
                default:
                    break;
                }
            }
            if (!enemy.death()) // If AI still alive
                enemy.AI(*human);
            else // AI died
            {
                cout << "YOU WIN" << endl;
                human->transfer(enemy); // player got all AI's items
            }
            if (human->death())
            {
                system("cls");
                cout << endl
                     << setw(50) << "GAME OVER" << endl;
                delete human;  // player is dead, program is getting to its end, what should we do here?
                system("pause");
                return 0;
            }
        }
    }
    delete human; // You win, program is getting to its end, what should we do here?
    system("cls");
    cout << "Congratulations! You defeated all opponents!!" << endl;
    system("pause");
    return 0;
}