实验5 继承和多态
2022.11.23 OOP实验课
实验5 继承和多态
任务1
验证性实验。
C++标准库提供了一个容器类模板map，称为关联数组或字典，可以用来描述键-值对映射关系。
在C++编码环境中，输入代码task1_1.cpp和 task1_2.cpp，结合运行结果，了解和练习map基础用法
task1-1.cpp(task15.cpp)
#include <iostream>
#include <map>
#include <string>
int main(){
using namespace std;
map<int, string> grade_dict{{5,"Excellent"},{4,"Good"},{3,"Average"},{2,"Fair"},{1,"Poor"}};
int grade;
while(cin >> grade){
if(grade >= 1 && grade <= 5){
cout << grade << ": " << grade_dict[grade] << endl;
}
else{
cout << "Invalid input. The number must be between 1 and 5.\n";
}
}
}
测试结果：
task1-2.cpp(task15.cpp)
#include <iostream>
#include <map>
#include <string>
#include <algorithm>
int main(){
using namespace std;
map<int, string> dec_hex_dict{{10,"A"},{11,"B"},{12,"C"},{13,"D"},{14,"E"},{15,"F"}};
for(int i = 10; i < 16; ++i){
cout << dec_hex_dict[i];
}
cout << endl;
string s1, s2, s3;
s1 = "FF17";
cout << "s1: " << s1 << endl;
reverse(s1.begin(), s1.end());//s1本身实现逆转
cout << "s1: " << s1 << endl;
s2 = string(s1.rbegin(), s1.rend());//s1本身没变，使用方向迭代器和构造函数，构造新串
cout << "s1: " << s1 << endl;
cout << "s2: " << s2 << endl;
}
测试结果：
map作为一个容器模板类，可以直观、方便地描述现实世界中的键-值对（Key-Value)关系。
从task1_2.cpp可见，实现对字符串逆转有多种方式，既可以使用迭代器，也可以使用算法库中的工具函数。根据问题场景，灵活组合使用标准库，可以极大提升开发效率，同时，代码也更简洁、安全、可读性也更好。
任务2
验证性实验：编译时多态 vs. 运行时多态（静态绑定 vs. 动态绑定）
graph.hpp(graph25.hpp)
#pragma once
#include <iostream>
#include <typeinfo>
//definiton of Graph
//abstract class
class Graph{
private:
std::string bgcolor;
public:
virtual void draw() = 0;//pure virtual function
};
//definition of Rectangle
//derived from Graph
class Rectangle: public Graph{
public:
void draw(){
std::cout << "draw a rectangle.\n";
}
};
//定义circle
//derived from Graph
class Circle: public Graph{
public:
void draw(){
std::cout << "draw a circle.\n";
}
};
task2.cpp(task25.cpp)
#include <iostream>
#include "graph25.hpp"
//定义一个函数func():as a call interface
void func(Graph *ptr){
std::cout << "pointer type: " << typeid(ptr).name() << "\n";
std::cout << "RTTI type: " << typeid(*ptr).name() << "\n";
ptr->draw();
}
void test(){
Rectangle r1;
func(&r1);
std::cout << std::endl;
Circle c1;
func(&c1);
}
int main(){
test();
}
运行结果：
由运行测试结果可见，接口函数 func() 中：
- 指针变量ptr的类型是确定的，是指向基类Graph的指针变量。
- 指针变量ptr指向的对象（ *ptr )的类型，是在运行时确定的。通过在基类中使用虚函数 draw() 实现在运行时根据指针实际指向的对象调用相应的绘图实现代码。
把基类Graph中的虚函数接口 draw() 替换成如下代码（line3)，重新编译、运行代码，观察这次结果有什么不同。
运行结果：
任务4
pets45.hpp
#pragma once
#include <iostream>
#include <string>
using namespace std;
class MachinePets{
private:
string nickname;
public:
MachinePets(const string s):nickname{s}{}
virtual string talk() = 0;
string get_nickname (){return nickname;}
};
class PetCats: public MachinePets{
public:
PetCats(const string s):MachinePets{s}{}
string talk(){
string cat = "miao wu~";
return cat;
}
};
class PetDogs: public MachinePets{
public:
PetDogs(const string s):MachinePets{s}{}
string talk(){
string dog = "wang wang~";
return dog;
}
};
task45.cpp
#include <iostream>
#include "pets45.hpp"
void play(MachinePets &obj){
std::cout << obj.get_nickname() << "says" << obj.talk() << std::endl;
}
void test(){
PetCats cat("miku");
PetDogs dog("da huang");
play(cat);
play(dog);
}
int main(){
test();
}
测试结果：
Tips*：
- 基类构造函数是需要参数为宠物昵称初始化的，因此，编写派生类构造函数时，注意其语法规则，需要为基类提供构造对象需要的参数
- 如果想让程序变得有趣些，可以查阅一些支持.midi或.wav的音频播放的工具函数，让电子宠物猫和电子宠物狗的talk()实现函数不是以文字形式呈现，而是以播放音频的方式呈现。
任务6
player65.h
#pragma once
//=======================
// player.h
//=======================
// The base class of player
// including the general properties and methods related to a character
#ifndef _PLAYER
#define _PLAYER
#include <iostream>
using std::string;
#include <iomanip> // use for setting field width
#include <time.h> // use for generating random factor
#include "container65.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
container65.h
#pragma once
//=======================
// container.h
//=======================
// The so-called inventory of a player in RPG games
// contains two items, heal and magic water
#ifndef _CONTAINER // Conditional compilation
#define _CONTAINER
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
swordsman65.h
#pragma once
//=======================
// swordsman.h
//=======================
// Derived from base class player
// For the job Swordsman
#include<iostream>
#include "player65.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
};
player65.cpp
//=======================
// player.cpp
//=======================
#include<iostream>
#include<iomanip>
#include "player65.h"
using namespace std;
// 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");
bag.set(bag.nOfHeal() + p.bag.nOfHeal(), bag.nOfMW() + p.bag.nOfMW());
// set the character's bag, get opponent's items
}
// 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;
}
container65.cpp
//=======================
// container.cpp
//=======================
#include <iostream>
#include "container65.h"
using namespace std;
// 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
}
swordsman65.cpp
//=======================
// swordsman.cpp
//=======================
#include <iostream>
#include"swordsman65.h"
using namespace std;
// 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();
}
}
}
}
main65.cpp
//=======================
// main.cpp
//=======================
// main function for the RPG style game
#include <iostream>
#include <string>
using namespace std;
#include "swordsman65.cpp"
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; // 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;
}
测试结果：
