实验5 类模板与多态
一、实验目的
1. 理解多态的概念，掌握编译时多态和运行时多态的区别
2. 掌握运算符重载函数的编写，理解编译器是如何将表达式转换为对运算符重载函数的调用的
3. 掌握虚函数的编写和灵活应用
4. 从多态角度理解函数模板、类模板（参数多态）
5. 灵活应用继承和多态编程解决现实世界的问题
实验任务2：
1 //Person.hpp 2 #include<iostream> 3 #include<string> 4 #include<iomanip> 5 using namespace std; 6 class Person 7 { 8 friend ostream& operator<<(ostream& out, const Person& p); 9 friend istream& operator>>(istream& in, Person& p); 10 friend bool operator==(const Person& p1, const Person& p2); 11 public: 12 Person() {} 13 Person(string name0, string telephone0) :name(name0), telephone(telephone0) {} 14 void change_Tel(string tel) 15 { 16 this->telephone = tel; 17 } 18 void change_email(string ema) 19 { 20 this->email = ema; 21 } 22 private: 23 string name; 24 string telephone; 25 string email; 26 }; 27 istream& operator>>(istream& in, Person& p) 28 { 29 getline(in, p.name); 30 getline(in, p.telephone); 31 getline(in, p.email); 32 cin.ignore(); 33 return in; 34 } 35 ostream& operator<<(ostream& out, const Person& p) 36 { 37 out << left << setw(20) << p.name << setw(20) << p.telephone << setw(20) << p.email; 38 return out; 39 } 40 bool operator==(const Person& p1, const Person& p2) 41 { 42 return p1.name == p2.name && p2.telephone == p1.telephone; 43 }
1 //task2.cpp 2 #include <iostream> 3 #include <fstream> 4 #include <vector> 5 #include "Person.hpp" 6 int main() 7 { 8 using namespace std; 9 vector<Person> phone_book; 10 Person p; 11 while (cin >> p) 12 phone_book.push_back(p); 13 for (auto& i : phone_book) 14 cout << i << endl; 15 cout << boolalpha << (phone_book.at(0) == phone_book.at(1)) << endl; 16 // save phone_book information to file 17 ofstream fout; 18 fout.open("phone_book.txt"); 19 if (!fout.is_open()) 20 { 21 cerr << "fail to open file phone_book.txt\n"; 22 return 1; 23 } 24 for (auto& i : phone_book) 25 fout << i << endl; 26 fout.close(); 27 }
运行结果截图（更改数据后）：
数据文件截图：
回答问题
① 在测试代码中， cout << i ，编译器会将这个表达式转换成什么样的函数调用？写出具体的函 数调用形式。
答：operator<<(cout,phone_book[i]);
② 在测试代码中， fout << i ，编译器会将这个表达式转换成什么样的函数调用？写出具体的函 数调用形式。
答：operator<<(fout,phone_book[i]);
实验任务3
补全后源码：
player.h
1 //======================= 2 // player.h 3 //======================= 4 5 // The base class of player 6 // including the general properties and methods related to a character 7 8 #ifndef _PLAYER 9 #define _PLAYER 10 #include <iomanip> // use for setting field width 11 #include <time.h> // use for generating random factor 12 #include "container.h" 13 using namespace std; 14 enum job {sw, ar, mg}; /* define 3 jobs by enumerate type 15 sword man, archer, mage */ 16 class player 17 { 18 friend void showinfo(player &p1, player &p2); 19 friend class swordsman; 20 21 protected: 22 int HP, HPmax, MP, MPmax, AP, DP, speed, EXP, LV; 23 // General properties of all characters 24 string name; // character name 25 job role; /* character's job, one of swordman, archer and mage, 26 as defined by the enumerate type */ 27 container bag; // character's inventory 28 29 public: 30 virtual bool attack(player &p)=0; // normal attack 31 virtual bool specialatt(player &p)=0; //special attack 32 virtual void isLevelUp()=0; // level up judgement 33 /* Attention! 34 These three methods are called "Pure virtual functions". 35 They have only declaration, but no definition. 36 The class with pure virtual functions are called "Abstract class", which can only be used to inherited, but not to constructor objects. 37 The detailed definition of these pure virtual functions will be given in subclasses. */ 38 39 void reFill(); // character's HP and MP resume 40 bool death(); // report whether character is dead 41 void isDead(); // check whether character is dead 42 bool useHeal(); // consume heal, irrelevant to job 43 bool useMW(); // consume magic water, irrelevant to job 44 void transfer(player &p); // possess opponent's items after victory 45 void showRole(); // display character's job 46 47 private: 48 bool playerdeath; // whether character is dead, doesn't need to be accessed or inherited 49 }; 50 51 #endif
main.cpp
1 //======================= 2 // main.cpp 3 //======================= 4 5 // main function for the RPG style game 6 7 #include <iostream> 8 #include <string> 9 using namespace std; 10 11 #include "swordsman.h" 12 13 14 int main() 15 { 16 string tempName; 17 bool success=0; //flag for storing whether operation is successful 18 cout <<"Please input player's name: "; 19 cin >>tempName; // get player's name from keyboard input 20 player *human; // use pointer of base class, convenience for polymorphism 21 human = NULL; 22 int tempJob; // temp choice for job selection 23 do 24 { 25 cout <<"Please choose a job: 1 Swordsman, 2 Archer, 3 Mage"<<endl; 26 cin>>tempJob; 27 system("cls"); // clear the screen 28 switch(tempJob) 29 { 30 case 1: 31 human=new swordsman(1,tempName); // create the character with user inputted name and job 32 success=1; // operation succeed 33 break; 34 default: 35 break; // In this case, success=0, character creation failed 36 } 37 }while(success!=1); // so the loop will ask user to re-create a character 38 39 int tempCom; // temp command inputted by user 40 int nOpp=0; // the Nth opponent 41 for(int i=1;nOpp<5;i+=2) // i is opponent's level 42 { 43 nOpp++; 44 system("cls"); 45 cout<<"STAGE" <<nOpp<<endl; 46 cout<<"Your opponent, a Level "<<i<<" Swordsman."<<endl; 47 system("pause"); 48 swordsman enemy(i, "Warrior"); // Initialise an opponent, level i, name "Junior" 49 human->reFill(); // get HP/MP refill before start fight 50 51 while(!human->death() && !enemy.death()) // no died 52 { 53 success=0; 54 while (success!=1) 55 { 56 showinfo(*human,enemy); // show fighter's information 57 cout<<"Please give command: "<<endl; 58 cout<<"1 Attack; 2 Special Attack; 3 Use Heal; 4 Use Magic Water; 0 Exit Game"<<endl; 59 cin>>tempCom; 60 switch(tempCom) 61 { 62 case 0: 63 cout<<"Are you sure to exit? Y/N"<<endl; 64 char temp; 65 cin>>temp; 66 if(temp=='Y'||temp=='y') 67 return 0; 68 else 69 break; 70 case 1: 71 success=human->attack(enemy); 72 human->isLevelUp(); 73 enemy.isDead(); 74 break; 75 case 2: 76 success=human->specialatt(enemy); 77 human->isLevelUp(); 78 enemy.isDead(); 79 break; 80 case 3: 81 success=human->useHeal(); 82 break; 83 case 4: 84 success=human->useMW(); 85 break; 86 default: 87 break; 88 } 89 } 90 if(!enemy.death()) // If AI still alive 91 enemy.AI(*human); 92 else // AI died 93 { 94 cout<<"YOU WIN"<<endl; 95 human->transfer(enemy); // player got all AI's items 96 } 97 if (human->death()) 98 { 99 system("cls"); 100 cout<<endl<<setw(50)<<"GAME OVER"<<endl; 101 // 6_??????????? 102 delete human;// player is dead, program is getting to its end, what should we do here? 103 system("pause"); 104 return 0; 105 } 106 } 107 } 108 // 7_??????????? 109 delete human; // You win, program is getting to its end, what should we do here? 110 system("cls"); 111 cout<<"Congratulations! You defeated all opponents!!"<<endl; 112 system("pause"); 113 return 0; 114 } 115
container.h
1 //======================= 2 // container.h 3 //======================= 4 5 // The so-called inventory of a player in RPG games 6 // contains two items, heal and magic water 7 //1_????????????? 8 #ifndef _CONTAINER 9 // Conditional compilation 10 #define _CONTAINER 11 12 class container // Inventory 13 { 14 protected: 15 int numOfHeal; // number of heal 16 int numOfMW; // number of magic water 17 public: 18 container(); // constuctor 19 void set(int heal_n, int mw_n); // set the items numbers 20 int nOfHeal(); // get the number of heal 21 int nOfMW(); // get the number of magic water 22 void display(); // display the items; 23 bool useHeal(); // use heal 24 bool useMW(); // use magic water 25 }; 26 27 #endif
container.cpp
1 //======================= 2 // container.cpp 3 //======================= 4 #include"container.h" 5 #include<iostream> 6 using namespace std; 7 // default constructor initialise the inventory as empty 8 container::container() 9 { 10 set(0,0); 11 } 12 13 // set the item numbers 14 void container::set(int heal_n, int mw_n) 15 { 16 numOfHeal=heal_n; 17 numOfMW=mw_n; 18 } 19 20 // get the number of heal 21 int container::nOfHeal() 22 { 23 return numOfHeal; 24 } 25 26 // get the number of magic water 27 int container::nOfMW() 28 { 29 return numOfMW; 30 } 31 32 // display the items; 33 void container::display() 34 { 35 cout<<"Your bag contains: "<<endl; 36 cout<<"Heal(HP+100): "<<numOfHeal<<endl; 37 cout<<"Magic Water (MP+80): "<<numOfMW<<endl; 38 } 39 40 //use heal 41 bool container::useHeal() 42 { 43 // 2_???????? 44 numOfHeal--; 45 return 1; // use heal successfully 46 } 47 48 //use magic water 49 bool container::useMW() 50 { 51 numOfMW--; 52 return 1; // use magic water successfully 53 }
swordsman.h
1 //======================= 2 // swordsman.h 3 //======================= 4 5 // Derived from base class player 6 // For the job Swordsman 7 8 #include "player.h" 9 //5_????????? 10 class swordsman : public player // subclass swordsman publicly inherited from base player 11 { 12 public: 13 swordsman(int lv_in=1, string name_in="Not Given"); 14 // constructor with default level of 1 and name of "Not given" 15 void isLevelUp(); 16 bool attack (player &p); 17 bool specialatt(player &p); 18 /* These three are derived from the pure virtual functions of base class 19 The definition of them will be given in this subclass. */ 20 void AI(player &p); // Computer opponent 21 };
swordsman.cpp
1 //======================= 2 // swordsman.cpp 3 //======================= 4 #include"swordsman.h" 5 #include<iostream> 6 using namespace std; 7 // constructor. default values don't need to be repeated here 8 swordsman::swordsman(int lv_in, string name_in) 9 { 10 role=sw; // enumerate type of job 11 LV=lv_in; 12 name=name_in; 13 14 // Initialising the character's properties, based on his level 15 HPmax=150+8*(LV-1); // HP increases 8 point2 per level 16 HP=HPmax; 17 MPmax=75+2*(LV-1); // MP increases 2 points per level 18 MP=MPmax; 19 AP=25+4*(LV-1); // AP increases 4 points per level 20 DP=25+4*(LV-1); // DP increases 4 points per level 21 speed=25+2*(LV-1); // speed increases 2 points per level 22 23 playerdeath=0; 24 EXP=LV*LV*75; 25 bag.set(lv_in, lv_in); 26 } 27 28 void swordsman::isLevelUp() 29 { 30 if(EXP>=LV*LV*75) 31 { 32 LV++; 33 AP+=4; 34 DP+=4; 35 HPmax+=8; 36 MPmax+=2; 37 speed+=2; 38 cout<<name<<" Level UP!"<<endl; 39 cout<<"HP improved 8 points to "<<HPmax<<endl; 40 cout<<"MP improved 2 points to "<<MPmax<<endl; 41 cout<<"Speed improved 2 points to "<<speed<<endl; 42 cout<<"AP improved 4 points to "<<AP<<endl; 43 cout<<"DP improved 5 points to "<<DP<<endl; 44 system("pause"); 45 isLevelUp(); // recursively call this function, so the character can level up multiple times if got enough exp 46 } 47 } 48 49 bool swordsman::attack(player &p) 50 { 51 double HPtemp=0; // opponent's HP decrement 52 double EXPtemp=0; // player obtained exp 53 double hit=1; // attach factor, probably give critical attack 54 srand((unsigned)time(NULL)); // generating random seed based on system time 55 56 // If speed greater than opponent, you have some possibility to do double attack 57 if ((speed>p.speed) && (rand()%100<(speed-p.speed))) // rand()%100 means generates a number no greater than 100 58 { 59 HPtemp=(int)((1.0*AP/p.DP)*AP*5/(rand()%4+10)); // opponent's HP decrement calculated based their AP/DP, and uncertain chance 60 cout<<name<<"'s quick strike hit "<<p.name<<", "<<p.name<<"'s HP decreased "<<HPtemp<<endl; 61 p.HP=int(p.HP-HPtemp); 62 EXPtemp=(int)(HPtemp*1.2); 63 } 64 65 // If speed smaller than opponent, the opponent has possibility to evade 66 if ((speed<p.speed) && (rand()%50<1)) 67 { 68 cout<<name<<"'s attack has been evaded by "<<p.name<<endl; 69 system("pause"); 70 return 1; 71 } 72 73 // 10% chance give critical attack 74 if (rand()%100<=10) 75 { 76 hit=1.5; 77 cout<<"Critical attack: "; 78 } 79 80 // Normal attack 81 HPtemp=(int)((1.0*AP/p.DP)*AP*5/(rand()%4+10)); 82 cout<<name<<" uses bash, "<<p.name<<"'s HP decreases "<<HPtemp<<endl; 83 EXPtemp=(int)(EXPtemp+HPtemp*1.2); 84 p.HP=(int)(p.HP-HPtemp); 85 cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl; 86 EXP=(int)(EXP+EXPtemp); 87 system("pause"); 88 return 1; // Attack success 89 } 90 91 bool swordsman::specialatt(player &p) 92 { 93 if(MP<40) 94 { 95 cout<<"You don't have enough magic points!"<<endl; 96 system("pause"); 97 return 0; // Attack failed 98 } 99 else 100 { 101 MP-=40; // consume 40 MP to do special attack 102 103 //10% chance opponent evades 104 if(rand()%100<=10) 105 { 106 cout<<name<<"'s leap attack has been evaded by "<<p.name<<endl; 107 system("pause"); 108 return 1; 109 } 110 111 double HPtemp=0; 112 double EXPtemp=0; 113 //double hit=1; 114 //srand(time(NULL)); 115 HPtemp=(int)(AP*1.2+20); // not related to opponent's DP 116 EXPtemp=(int)(HPtemp*1.5); // special attack provides more experience 117 cout<<name<<" uses leap attack, "<<p.name<<"'s HP decreases "<<HPtemp<<endl; 118 cout<<name<<" obtained "<<EXPtemp<<" experience."<<endl; 119 p.HP=(int)(p.HP-HPtemp); 120 EXP=(int)(EXP+EXPtemp); 121 system("pause"); 122 } 123 return 1; // special attack succeed 124 } 125 126 // Computer opponent 127 void swordsman::AI(player &p) 128 { 129 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))) 130 // AI's HP cannot sustain 3 rounds && not too lavish && still has heal && won't be killed in next round 131 { 132 useHeal(); 133 } 134 else 135 { 136 if(MP>=40 && HP>0.5*HPmax && rand()%100<=30) 137 // AI has enough MP, it has 30% to make special attack 138 { 139 specialatt(p); 140 p.isDead(); // check whether player is dead 141 } 142 else 143 { 144 if (MP<40 && HP>0.5*HPmax && bag.nOfMW()) 145 // Not enough MP && HP is safe && still has magic water 146 { 147 useMW(); 148 } 149 else 150 { 151 attack(p); // normal attack 152 p.isDead(); 153 } 154 } 155 } 156 }
player.cpp
1 //======================= 2 // player.cpp 3 //======================= 4 5 #include"player.h" 6 #include<iostream> 7 using namespace std; 8 // character's HP and MP resume 9 void player::reFill() 10 { 11 HP=HPmax; // HP and MP fully recovered 12 MP=MPmax; 13 } 14 15 // report whether character is dead 16 bool player::death() 17 { 18 return playerdeath; 19 } 20 21 // check whether character is dead 22 void player::isDead() 23 { 24 if(HP<=0) // HP less than 0, character is dead 25 { 26 cout<<name<<" is Dead." <<endl; 27 system("pause"); 28 playerdeath=1; // give the label of death value 1 29 } 30 } 31 32 // consume heal, irrelevant to job 33 bool player::useHeal() 34 { 35 if(bag.nOfHeal()>0) 36 { 37 HP=HP+100; 38 if(HP>HPmax) // HP cannot be larger than maximum value 39 HP=HPmax; // so assign it to HPmax, if necessary 40 cout<<name<<" used Heal, HP increased by 100."<<endl; 41 bag.useHeal(); // use heal 42 system("pause"); 43 return 1; // usage of heal succeed 44 } 45 else // If no more heal in bag, cannot use 46 { 47 cout<<"Sorry, you don't have heal to use."<<endl; 48 system("pause"); 49 return 0; // usage of heal failed 50 } 51 } 52 53 // consume magic water, irrelevant to job 54 bool player::useMW() 55 { 56 if(bag.nOfMW()>0) 57 { 58 MP=MP+100; 59 if(MP>MPmax) 60 MP=MPmax; 61 cout<<name<<" used Magic Water, MP increased by 100."<<endl; 62 bag.useMW(); 63 system("pause"); 64 return 1; // usage of magic water succeed 65 } 66 else 67 { 68 cout<<"Sorry, you don't have magic water to use."<<endl; 69 system("pause"); 70 return 0; // usage of magic water failed 71 } 72 } 73 74 // possess opponent's items after victory 75 void player::transfer(player &p) 76 { 77 cout<<name<<" got"<<p.bag.nOfHeal()<<" Heal, and "<<p.bag.nOfMW()<<" Magic Water."<<endl; 78 system("pause"); 79 // 3_??????????? 80 bag.set(bag.nOfHeal() + p.bag.nOfHeal(), bag.nOfMW() + p.bag.nOfMW()); 81 // set the character's bag, get opponent's items 82 } 83 84 // display character's job 85 void player::showRole() 86 { 87 switch(role) 88 { 89 case sw: 90 cout<<"Swordsman"; 91 break; 92 case ar: 93 cout<<"Archer"; 94 break; 95 case mg: 96 cout<<"Mage"; 97 break; 98 default: 99 break; 100 } 101 } 102 103 // 4_?????????????? 104 // display character's job 105 void showinfo(player& p1, player& p2) 106 { 107 system("cls"); 108 cout<<"##############################################################"<<endl; 109 cout<<"# Player"<<setw(10)<<p1.name<<" LV. "<<setw(3) <<p1.LV 110 <<" # Opponent"<<setw(10)<<p2.name<<" LV. "<<setw(3) <<p2.LV<<" #"<<endl; 111 cout<<"# HP "<<setw(3)<<(p1.HP<=999?p1.HP:999)<<'/'<<setw(3)<<(p1.HPmax<=999?p1.HPmax:999) 112 <<" | MP "<<setw(3)<<(p1.MP<=999?p1.MP:999)<<'/'<<setw(3)<<(p1.MPmax<=999?p1.MPmax:999) 113 <<" # HP "<<setw(3)<<(p2.HP<=999?p2.HP:999)<<'/'<<setw(3)<<(p2.HPmax<=999?p2.HPmax:999) 114 <<" | MP "<<setw(3)<<(p2.MP<=999?p2.MP:999)<<'/'<<setw(3)<<(p2.MPmax<=999?p2.MPmax:999)<<" #"<<endl; 115 cout<<"# AP "<<setw(3)<<(p1.AP<=999?p1.AP:999) 116 <<" | DP "<<setw(3)<<(p1.DP<=999?p1.DP:999) 117 <<" | speed "<<setw(3)<<(p1.speed<=999?p1.speed:999) 118 <<" # AP "<<setw(3)<<(p2.AP<=999?p2.AP:999) 119 <<" | DP "<<setw(3)<<(p2.DP<=999?p2.DP:999) 120 <<" | speed "<<setw(3)<<(p2.speed<=999?p2.speed:999)<<" #"<<endl; 121 cout<<"# EXP"<<setw(7)<<p1.EXP<<" Job: "<<setw(7); 122 p1.showRole(); 123 cout<<" # EXP"<<setw(7)<<p2.EXP<<" Job: "<<setw(7); 124 p2.showRole(); 125 cout<<" #"<<endl; 126 cout<<"--------------------------------------------------------------"<<endl; 127 p1.bag.display(); 128 cout<<"##############################################################"<<endl; 129 }
运行结果截图：
