c++ primer plus第十章习题答案

第一题到第八题已经补全，但是第八题个人理解按照题上的说法做，即函数指针，没有什么意义。也有可能是我没有理解清楚题意吧。我想明白后会回来再做修改，也希望各位能提一些意见一起探讨！

第一题

count.h

//***************************************************************************************////*****************************************count.h***************************************//#ifndef COUNT_H_#define COUNT_H_#include <string>class BankCount{private:std::string m_name;double m_countNum;double m_deposit;public:BankCount();BankCount(const std::string &co, double recvCountNum = 0, double recvDeposit = 0);~BankCount();void addr();void input(const double store);void output(const double expense);void display() const;// promises not to change invoking object};#endif//***************************************************************************************//

count.cpp

#include <iostream>#include <iomanip>#include "count.h"BankCount::BankCount()// default constructor{std::cout << "Default constructor called.\n";m_name = "NULL";m_countNum = 0;m_deposit = 0;}BankCount::BankCount(const std::string &co, double countNum, double deposit){std::cout << "Constructor using " << co << " called.\n";m_name = co;m_countNum = countNum;if(deposit < 0)//--------------------------string object duplicate?????????????????{std::cout << "Initial deposit money can not be negative."<<" Deposit money is set to 0.\n\n";m_deposit = 0;}else{m_deposit = deposit;}}BankCount::~BankCount(){std::cout << "Bye!\n";}void BankCount::addr(void){std::cout << (void *)&m_name << "\n";}void BankCount::input(const double store){if(store < 0){std::cout << "Number of storing money can not be negative.\n\n";}else{m_deposit = m_deposit + store;std::cout << "$" << store << " is stored.\n\n";}}void BankCount::output(const double expense){if(expense <= 0){std::cout << "Number of expensed money can not be negative.\n\n";}else{if(expense - m_deposit){std::cout << "Number of expensing money exceeds deposit money.\n"<< "Deposit money is $" << m_deposit << ".\n\n";}else{m_deposit = m_deposit - expense;std::cout << "$" << expense << " is expensed.\n\n";}}}void BankCount::display() const{using namespace std;std::cout << m_name << ": \n";std::cout << setprecision(20) << "Count number: " << m_countNum << ".\n";std::cout << "Deposit money: $" << m_deposit << ",\n\n";}

main.cpp

#include <iostream>#include <stdlib.h>#include "count.h"int main(){double moneyinput,moneyoutput;int execute = 0;std::string a = "Mark Wall";BankCount member1(a, 1001001101001100, 30000);std::cout << (void *)&a << "\n";member1.addr();member1.display();while(execute != 4){std::cout << "Choose the option:\n"<< "1. Enter the number of money you want to store: \n"<< "2. Enter the number of money you want to expense:; \n"<< "3. Display your count.\n"<< "4. Quit.\n";std::cin >> execute;switch(execute){case 1:std::cout << "Enter the money: ";std::cin >> moneyinput;member1.input(moneyinput);break;case 2:std::cout << "Enter the money: ";std::cin >> moneyoutput;member1.output(moneyoutput);break;case 3:member1.display();break;case 4:break;default:std::cout << "Wrong choose!\n";}}return 0;}

第二题

person.h

//*************************************************************************////**********************************person.h*******************************//#ifndef PERSON_H_#define PERSON_H_#include <string>class Person{private:static const int LIMIT = 25;std::string lname;// Person's last namechar fname[LIMIT];// Person's first namepublic:Person() {lname = ""; fname[0] = '\0';}// #1Person(const std::string & ln, const char * fn = "Heyyou");// #2~Person();// the following methods display lname and fnamevoid Show() const;// firstname lastname formatvoid FormalShow() const;// lastname, firstname formatvoid Addr() const;};#endif//*************************************************************************//

person.cpp

#include <iostream>#include <cstring>#include "person.h"Person::Person(const std::string & ln, const char * fn){int str;lname = ln;str = strlen(fn);std::cout << "length of first name: " << str << std::endl;strncpy(fname, fn, str+1);}Person::~Person(){std::cout << "Bye\n";}void Person::Show(void) const{std::cout << fname << " " << lname << "\n";}void Person::FormalShow(void) const{std::cout << lname << " " << fname << "\n";}void Person::Addr(void) const{std::cout << "Address of char is " << (void *)fname << ". This address is the address of string\n";std::cout << "Address of string class is " << &lname << ". This address is not the address of string\n";//std::cout <<  << std::endl;  //how to output the address of string in the class string?}

main.cpp

#include <iostream>#include <string>#include "person.h"using namespace std;int main(){Person one;// use default constructorPerson two("Smythecraft");// use #2 with one default argumentPerson three("Dimwiddy", "Sam");// use #2, no defaultscout << endl;cout << "Address of two's \"Smythecraft\" is " << (void *)"Smythecraft" << endl << endl;;one = two;one.Show();one.FormalShow();one.Addr();cout << endl;one = Person();two.Show();two.FormalShow();two.Addr();cout << endl;three.Show();three.FormalShow();three.Addr();cout << endl;return 0;}

第三题

golf.h

//*****************************************************************////*******************************golf.h****************************//// golf.h -- for pe9-1.cpp#ifndef GOLF_H_#define GOLF_H_class Golf{private:static const int LEN = 40;char m_fullname[LEN];int m_handicap;public:// non-interactive version:// function sets golf structure to provided name, handicap// using values passed as arguments to the functionGolf() {m_fullname[0] = '\0'; m_handicap = 0;}Golf(const char * name, const int hc);~Golf();// interactive version:// fuction solicits name and handicap from user// and sets the members of g to the values entered// returns 1 if name is entered, 0 if name is empty stringGolf setgolf();// function resets handicap to new valuevoid handicap(int hc);// function displays contents of golf structurevoid showgolf() const;};#endif//*****************************************************************//

golf.cpp

#include <iostream>#include <cstring>#include "golf.h"extern int ret;Golf::Golf(const char * name, const int hc){strcpy_s(m_fullname, name);m_handicap = hc;}Golf::~Golf(){//}Golf Golf::setgolf(void){using namespace std;char fullname[40];int handicap;cout << "Enter fullname less than 40 words:" << endl;cin.getline(fullname,40);if(fullname[0] == '\0')ret = 0;else{cout << "Enter handicap:" << endl;cin >> handicap;cin.get();*this = Golf(fullname, handicap);}return *this;}void Golf::handicap(int hc){m_handicap = hc;}void Golf::showgolf(void) const{using namespace std;cout << "fullname: " << m_fullname << endl;cout << "handicap: " << m_handicap << endl;}

main.cpp

#include <iostream>#include "golf.h"int ret = 1;int main(){Golf ann[10];int count = 0;do{if(count%2 == 0){ann[count] = ann[count].setgolf();}else{using namespace std;char temp[40];int num;cout << "Enter fullname less than 40 words:" << endl;cin.getline(temp,40);if(temp[0] == '\0'){break;}else{//}cout << "Enter handicap:" << endl;cin >> num;cin.get();ann[count] = Golf(temp, num);}count ++;}while((ret == 1)&&(count < 10));ann[0].showgolf();ann[0].handicap(6);ann[0].showgolf();return 0;}

第四题

sales.h

//***********************************************////*******************sales.h*********************//#ifndef SALES_H_#define SALES_Hnamespace SALES{class Sales{private:static const int QUARTERS = 4;double sales[QUARTERS];double average;double max;double min;void findaver(int n);void findmax(int n);void findmin(int n);public:// copies the lesser of 4 or n items from the array ar// to the sales member of s and computes and stores the// average, maximum, and minimum values of the entered items;// remaining elements of sales, if any, set to 0Sales() {sales[0] = '\0'; average = 0; max = 0; min = 0;}Sales(const double ar[], int n);~Sales(){}// gathers sales for 4 quarters interactively, stores them// in the sales member of s and computes and stores the// average, maximum, and minimum valuesSales setSales();// display all information in structure svoid showSales() const;};}#endif SALES_H_//***********************************************//

sales.cpp

#include <iostream>#include <stdlib.h>#include "sales.h"namespace SALES{Sales::Sales(const double ar[], int n){using std::cout;if(n > 4 || n < 0){cout << "error! n is out of range.\n";_exit(-1);// force to quit the whole program}// exit(0),exit(non-0),_exit(0),_exit(non-0) is different from each other.else// _exit(): loss the data in the buffer, exit(): hold the data in the buffer{// exit(0): quit normally, exit(non-0): quit abnormallyfor(int i = 0; i < n; i++)sales[i] = ar[i];findaver(n);findmax(n);findmin(n);for(int i = 0; i < 4; i++)sales[i] = 0;}}Sales Sales::setSales(void){using std::cout;using std::cin;int n;double temp[4];cout << "Set the sales number no more than 4: ";cin >> n;if(n > 4 || n < 0){cout << "error! n is out of range.\n";_exit(-1);}else{for(int i = 0; i < n; i++){cout << "input the #" << i+1 << " sale: ";cin >> temp[i];}*this = Sales(temp, n);return *this;}}void Sales::findaver(int n){double total = 0;for(int i = 0; i < n; i++){total = total + sales[i];}average = total / n;}void Sales::findmax(int n){max = sales[0];// initialize max and min, compare with each onefor(int i = 0; i < n; i++){if(sales[i] > max)max = sales[i];}}void Sales::findmin(int n){min = sales[0];for(int i = 0; i < n; i++){if(sales[i] < min)min = sales[i];}}void Sales::showSales() const{using std::cout;using std::endl;cout << endl << endl;;cout << "average of sale is " << average << endl;cout << "max value of sale is " << max << endl;cout << "min value of sale is " << min << endl;}}

main.cpp

#include "sales.h"using namespace SALES;int main(){double a[] = {3,4,5,6};Sales obj1(a, 4), obj2;obj2 = obj2.setSales();obj1.showSales();obj2.showSales();return 0;}

第五题

stack.h

//**********************************************************************////*********************************stack.h******************************//#ifndef STACK_H_#define STACK_H_typedef struct{char fullname[35];double payment;}customer;class Stack{private:static const int MAX = 10;//constant specific to classcustomer m_items[MAX];// holds stack itemsint m_top;// index for top stack itemdouble m_gloss;// store total valuepublic:Stack();~Stack();bool isempty() const;bool isfull() const;// push() returns false if stack already is full, true otherwisebool push(const customer & obj);// add item to stack// pop() returns false if stack already is empty, true otherwisebool pop(customer & obj);// pop top into itemvoid show() const;// show payment};#endif//**********************************************************************//

stack.cpp

#include <iostream>#include <cstring>#include "stack.h"Stack::Stack(){m_top = 0;m_gloss = 0;}Stack::~Stack(){//}bool Stack::isempty(void) const{return (m_top == 0);}bool Stack::isfull(void) const{return (m_top == MAX);}bool Stack::push(const customer & obj){if(m_top < MAX){m_items[m_top].payment = obj.payment;int str;// statement can be put in wherever but before being usedstr = strlen(obj.fullname);strncpy_s(m_items[m_top].fullname, obj.fullname, str+1);m_top++;return true;}elsereturn false;}bool Stack::pop(customer & obj){if(m_top > 0){int str;m_top--;m_gloss = m_gloss + m_items[m_top].payment;// add the value of payment to glossobj.payment = m_items[m_top].payment;str = strlen(m_items[m_top].fullname);strncpy_s(obj.fullname, m_items[m_top].fullname, str+1);return true;}elsereturn false;}void Stack::show(void) const{std::cout << "\n" << "Now " << m_top << " elements are in stack.\n"<< "The point \"top\" is pointing to " << m_top << ".\n"<< "The total number of payment is " << m_gloss << "\n";}

main.cpp

#include <iostream>#include "stack.h"void showobj(customer obj, int n){std::cout << "#" << n+1 << ": " << obj.fullname << ": " << obj.payment << "\n";}int main(){Stack obj_stack;customer recv[11] = {};// 初始化customer object[11] = {// 如果不初始化，每个元素里将有随机值，输出乱码{"Adobe Reader", 1.1},// 初始化后如果某位或几位为缺省，则对应元素为0{"Microsoft Office", 2.2},{"Photo Shop", 3.3},{"Surface Pro", 4.4},{"Google Chrome", 5.5},{"Quartus II", 6.6},{"Daemon Tools", 7.7},{"VM Ware", 8.8},{"TuneUp", 9.9},{"Sketch Up", 10},{"Whatever", 11.11}};for(int i = 0; i < 11; i++)showobj(object[i], i);// 输出将要压入栈的元素obj_stack.show();// 输出此时栈的情况while(!obj_stack.isfull()){static int j = 0;while(!obj_stack.push(object[j]))// 压栈，如果成功将不执行while语句{// 应该不会出现失败的情况，std::cout << "Unknown push error!\n";// 之所以这样写是处于个人习惯_exit(1);}j++;}obj_stack.show();while(!obj_stack.isempty())// 出栈，原理同上{static int k = 0;while(!obj_stack.pop(recv[k])){std::cout << "Unknown pop error!\n";_exit(1);}k++;}obj_stack.show();// 输出此时栈的情况std::cout << std::endl;for(int i = 0; i < 11; i++)showobj(recv[i], i);// 输出接收器接收的数据return 0;}

第六题

move.h

//****************************************************************************////**********************************move.h************************************//#ifndef MOVE_H_#define MOVE_H_class Move{private:double x;double y;public:Move(double a = 0, double b = 0);// sets x, y to a, b~Move() {}void showmove() const;// shows current x, y valuesMove add(const Move & m) const;// this function adds x of m to x of invoking object to get new x,// adds y of m to y of invoking object to get new y, creates a new// move object initialized to new x, y values and returns itvoid reset(double a = 0, double b = 0);// resets x, y to a, b};#endif//****************************************************************************//

move.cpp

#include <iostream>#include "move.h"Move::Move(double a, double b){x = a;y = b;}void Move::showmove(void) const{std::cout << "current x = " << x << "\n"<< "current y = " << y << "\n\n";}Move Move::add(const Move & m) const{double xt = x + m.x;double yt = y + m.y;return (Move(xt, yt));}void Move::reset(double a, double b){x = a;y = b;}

main.cpp

#include <iostream>#include "move.h"int main(){Move obj1;Move obj2(1.1, 2.2);Move obj3 = Move(3.3, 4.4);std::cout << "object1:\n";obj1.showmove();std::cout << "object2:\n";obj2.showmove();std::cout << "object3:\n";obj3.showmove();std::cout << "after 1st addition, object3:\n";obj3 = obj1.add(obj2);obj3.showmove();std::cout << "after 2nd addition, object3:\n";obj3 = obj3.add(obj2);// 合法，等号右边创建临时对象，没有修改obj3，obj3.showmove();// 把临时对象赋给obj3，这时obj3已经不是conststd::cout << "after reset, object3:\n";obj3.reset(1, 1);obj3.showmove();return 0;}

第七题

plorg.h

//**************************************************************************////*********************************plorg************************************//#ifndef PLORG_H_#define PLORG_H_class Plorg{private:enum {MAX = 20};char m_name[MAX];int m_CI;public:Plorg();Plorg(char * s);~Plorg() {}void changeCI(int temp);void show() const;};#endif//**************************************************************************//

plorg.cpp

#include <iostream>#include <cstring>#include "plorg.h"Plorg::Plorg(){strcpy(m_name, "Plorga");m_CI = 50;}Plorg::Plorg(char * s){int str = strlen(s);//strncpy_s(m_name, 20, s, str+1);strncpy_s(m_name, s, str+1);// 与上一句等效，拷贝19和str中较小的字符数，在结尾处加'\0'// 实际测试中发现拷贝字符数多于19个时强制退出并报错m_CI = 50;}void Plorg::changeCI(int temp){m_CI = temp;}void Plorg::show(void) const{std::cout << "plorg name: " << m_name << "\n"<< "plorg CI: " << m_CI << "\n";}

main.cpp

#include <iostream>#include <string>#include "plorg.h"int main(){using namespace std;//char na[24]= "asdfasdfasdfasdfasdfas";string name;Plorg obj1;Plorg obj2("Betelgeusean");cout << "object1:\n";obj1.show();cout << "object2:\n";obj2.show();cout << "Enter the name of object1 less than 20 words: ";getline(cin, name);Plorg obj3((char *)name.c_str());// name是string类的对象，字符串地址需要通过方法c_str得到//Plorg obj3(na);// 直接对name取址得到的是对象地址obj3.show();obj2.changeCI(60);cout << "object2:\n";obj2.show();return 0;}

第八题

list.h

//********************************************************************************////************************************list.h**************************************//#ifndef LIST_H_#define LIST_H_typedef int Item;// 默认Item为int型，可以换为其他基本数据类型，不能为结构体//typedef double Item;//typedef float Item;//typedef short Item;//typedef char Item;void show(Item &);class List{private:void * m_pt;// 设置成空指针是为了能够指向任意类型的数据int m_pos;// 标记表示当前存储数据的位置，实际上是数组中下一个为空的位置，类似于栈int m_MAX;// 存储列表可容纳的数据个数public:List();List(const int n);~List();bool isempty() const;bool isfull() const;bool add(const Item &);void visit(void (*pt)(Item &)) const;};#endif//********************************************************************************//

list.cpp

#include <iostream>#include "list.h"List::List(){//m_pt = new int [1];// 只有一个int型0元素的列表//*(int *)m_pt = 0;//m_MAX = 1;//m_pos = 1;m_pt = NULL;// 指针指向空，空列表m_pos = 0;m_MAX = 0;}List::List(const int n){m_pt = new Item [n];m_pos = 0;m_MAX = n;(Item *)m_pt;}List::~List(){delete [] m_pt;// 在析构函数里要把m_pt指针指向的空间释放}bool List::isempty(void) const{return (m_pos == 0);}bool List::isfull(void) const{return (m_pos == m_MAX);}bool List::add(const Item & item){if(isfull())return false;else{*((Item *)m_pt+(m_pos++)) = item;// 强制转换m_pt指向的数据类型，后面加偏移地址return true;}}void List::visit(void (*pt)(Item &)) const// 该函数隐式访问类内数据，接收函数指针为参数{int flag = 0;// 标记没有找到数据Item item;// item是函数指针指向的函数的参数，要在visit内声明std::cout << "Enter the element you want to visit: ";std::cin >> item;for(int i = 0; i < m_pos; i++){if(item == *((Item *)m_pt+i))// 左值，要找的参数；右值，列表中的数据{std::cout << "Find " << item << " in position " << i+1 << std::endl;(*pt)(item);flag++;}}if(flag == 0)std::cout << "No such item has been found!\n";}void show(Item & item)// 这个函数有什么意义我还没有想明白，莫非只是为了展示一下{// 函数指针技术？弄清楚后会回来补充std::cout << item << "\n";}

main.cpp

#include <iostream>#include "list.h"int main(){using std::cout;using std::cin;List Tlist(5);// 可以交互式输入列表容量，为了简单直接给5Item temp;int option = 0;while(option != 5){cout << "choose the option:\n";cout << "1. check if the list is empty.\n"<< "2. check if the list is full.\n"<< "3. add element to the list.\n"<< "4. visit a element.\n"<< "5. quit.\n";cin >> option;switch(option){case 1:if(Tlist.isempty())// 检查是否为空cout << "The list is empty.\n";elsecout << "The list is not empty.\n";break;case 2:if(Tlist.isfull())// 检查是否为满cout << "The list is full.\n";elsecout << "The list is not full.\n";break;case 3:if(!Tlist.isfull())// 不为空时可以添加数据{cout << "Enter the item you want to add in: ";cin >> temp;if(Tlist.add(temp))cout << "Add operation Succeed!\n";elsecout << "Add operation fail!\n";}elsecout << "The list is already full!\n";break;case 4:// 查找元素if(!Tlist.isempty())Tlist.visit(show);elsecout << "The list is empty, no element exists!\n";break;case 5:break;default:cout << "Entered the wrong number, please enter again: ";}cout << std::endl;}cout << "Bye!\n";return 0;}