c++ Primer Plus（第六版）第十七章习题，写代码之路

c++ Primer Plus（习题17.1)

//编写一个程序计算$之前的字符数，并且把它留在输入流中#include<iostream>int main(){using namespace std;cout << "Enter a text,report the number(end with $):\n";int count=0;char r;while (cin.peek()!='$')//peek方法查看下一个字符{cin.get(r);//用<<读取会跳过空格if (r != '$'){cout << r;count++;}}char next;cin >> next;cout << "\nThe number of character is: " << count << endl;cout << "And the next character is: " << next << endl;return 0;}

c++ Primer Plus（习题17.2)

//将键盘输入弄到文件里面，直到模拟的文件结尾#include<iostream>#include<fstream>#include<string>int main(int argc,char *argv[]){using namespace std;if (argc != 2){cerr << "Usage: " << argv[0] << " filename[s]\n";exit(EXIT_FAILURE);}ofstream fin;fin.open(argv[1]);//这是命令行的第二个参数if (!fin.is_open()){cerr << "Could not open " << argv[0] << "\n";exit(EXIT_FAILURE);}cout << "Give me something you want add to the file(<CTRL>+<Z>+<ENTER> to end): ";string  ch;while (cin.fail()==false)//这里是用输入流的方法来检查文件结尾{getline(cin, ch);cout << ch;fin << ch;}cout << "Input complete!\n";fin.close();return 0;}

c++ Primer Plus（习题17.3)

//和上一题差不多，不过是将一个文件的内容复制到另一个文件//也是用命令行来指定文件的参数#include<iostream>#include<fstream>int main(int argc, char *argv[]){using namespace std;if (argc != 3){cerr << "Usage: " << argv[0] << " resource filename[s] target[s]\n";exit(EXIT_FAILURE);}ofstream fin;fin.open(argv[2]);//这是命令行的第二个参数if (!fin.is_open()){cerr << "Could not open " << argv[0] << "\n";exit(EXIT_FAILURE);}ifstream fou;fou.open(argv[1]);if (!fou.is_open()){cerr << "Could not open " << argv[0] << "\n";exit(EXIT_FAILURE);}char c;while (fou.get(c)){cout << c;fin.put(c);//逐字符读取和写入}cout << "\nCopy complete!\n";//程序出现一个问题，就是会把源文件最后的字符写入两下到目标文件中fou.close();fin.close();return 0;}

c++ Primer Plus（习题17.4)

//三个文件的输入输出，对文件进行拼接，并写入到第三个文件中//这个程序是让用户给出两个文件的内容，然后程序显示拼接后的结果//输出文件有个小小的空格，这个问题很小，可是我不知道#include<iostream>#include<fstream>#include<cstdlib>#include<string>int main(){using namespace std;ofstream fin;cout << "This program is connect two file content to another file.\n";cout << "Enter the frist filename: ";string filename;getline(cin, filename);fin.open(filename.c_str());cout << "Now,give me something to the frist resource file:\n";string file;while (cin.fail() == false)//检查文件尾{getline(cin, file);fin<<file << endl;}fin.close();cin.clear();cout << "Enter the second filename: ";string filename2;getline(cin, filename2);fin.open(filename2.c_str());cout << "Now,give me someing to the second resource file:\n";while (cin.fail() == false){getline(cin, file);fin<<file << endl;}fin.close();cin.clear();cout << "Enter the target filename: ";string target;getline(cin, target);fin.open(target.c_str());ifstream fou,fou2;fou.open(filename);fou2.open(filename2);if (!fou.is_open()||!fou2.is_open()){cerr << "Could not open the source!"<<filename<<endl<<filename2<< "\n";exit(EXIT_FAILURE);}string file2;while (!fou.eof()&&!fou2.eof()){getline(fou, file);getline(fou2, file2);fin << file + ' ' + file2 << endl;cout<< file + ' ' + file2 << endl;}while (!fou.eof()){getline(fou, file);fin << file << endl;cout << file << endl;}while (!fou2.eof()){getline(fou2, file);fin << file << endl;cout << file << endl;}fou.close();fou2.close();fin.close();return 0;}

c++ Primer Plus（习题17.5)

//这题和16章的差不多，不过是在文件里面读取名字到容器里面//所以自己准备好名字，容器这里有#include<iostream>#include<fstream>#include<string>#include<set>#include<algorithm>#include<iterator>//迭代器的头文件int main(){using namespace std;ostream_iterator<string, char>out(cout, "\n");//输出迭代器ifstream fin;char filename[10];set<string>fresource;char temp[10];string file;cout << "Enter the Mat friends filename: ";cin.getline(filename, 10);fin.open(filename);if (!fin.is_open()){cerr << "Cant open the file " << filename << endl;exit(EXIT_FAILURE);}while (!fin.eof()){fin.getline(temp,10);fresource.insert(temp);//用插入元素的方法cout << temp<<endl;}fin.close();cout << "Enter the Pat friends filename: ";cin.getline(filename, 10);fin.open(filename);if (!fin.is_open()){cerr << "Cant open the file " << filename << endl;exit(EXIT_FAILURE);}set<string>fresource2;//建立第二个容器while (!fin.eof()){fin.getline(temp, 10);fresource2.insert(temp);cout << temp << endl;}fin.close();cout << "Enter the Target filename: ";cin.getline(filename, 10);ofstream fou;fou.open(filename);set<string>target;//还是书上的老方法，用一个匿名的插入迭代器set_union(fresource.begin(), fresource.end(), fresource2.begin(), fresource2.end(),insert_iterator<set<string>>(target, target.begin()));cout << "Friends they have:\n";copy(target.begin(), target.end(), out);ostream_iterator<string, char>fileout(fou, "\n");//输出到文件迭代器,自己起名的copy(target.begin(), target.end(), fileout);fou.close();return 0;}

c++ Primer Plus（习题17.6)

//第十七章的17.6题，跟前面14.5的相似，不过是添加了一点东西//书上提供了解决方案，添加数据到文件中，保存读写数据的方法//对了，书上的getall（）方法个人觉得是要带参数的//这题打出来之后出现已有主体C2084错误,原因是该函数重定义了//去掉之后出现错误LNK2001，又是这个类设计很常见，起码是我这里很常见的//主要是无法识别的外部命令,//错误原因：empoyee的虚函数没有定义//我的文件读取方式是/*0TripHarrisThumper*/#include<iostream>using namespace std;#include"fileemp.h"const int MAX = 10;void showClassType();int main(void){abstr_emp *pc[MAX];//不可以创建抽象类型的数组，但是可以创建指针cout << "This program show the file of class Empoyee,input the data name to continue.\n";cout << "Enter the target file:";char filename[MAX];cin.getline(filename, MAX);ifstream fin;fin.open(filename);if (!fin.is_open()){cerr << "Sorry ,can't open " << filename << endl;exit(EXIT_FAILURE);}char ch;int i = 0;int classtype;while (fin >> classtype){switch (classtype){case Employee:pc[i] = new employee; break;case Manager:pc[i] = new manager; break;case Fink:pc[i] = new fink; break;case Highfink:pc[i] = new highfink; break;}pc[i]->getall(fin);pc[i]->ShowAll();i++;}fin.close();ofstream fou;fou.open(filename, ios_base::out | ios_base::app);//追加模式打开文件int idex=0;showClassType();while (cin >> ch&&ch != 'q'&&idex < MAX){cin.get();switch (ch){case 'a':pc[idex]= new employee;pc[idex]->SetAll();break;case 'b':pc[idex] = new manager;pc[idex]->SetAll(); break;case 'c':pc[idex] = new fink;pc[idex]->SetAll(); break;case 'd':pc[idex] = new highfink;pc[idex]->SetAll(); break;default:cout << "Error type!\n"; break;}idex++;showClassType();}for (i = 0; i < idex; i++)pc[i]->writeall(fou);fou.close();fin.clear();fin.open(filename);cout << "Here is the redice file:\n";while ((fin >> classtype).get(ch)){switch (classtype){case Employee:pc[i] = new employee; break;case Manager:pc[i] = new manager; break;case Fink:pc[i] = new fink; break;case Highfink:pc[i] = new highfink; break;}pc[i]->getall(fin);pc[i]->ShowAll();i++;}fin.close();cout << "Bye!\n";return 0;}void showClassType(){cout << "What class type do you want to creat:\n ""a)Employee  b)Manage  c)Fink  d)Highfink  q)quit\n";}

#pragma once#pragma execution_character_set("utf-8")//本文件为utf-8编码格式#pragma once#pragma execution_character_set("utf-8")//本文件为utf-8编码格式//这个头文件属于14.5题书上提供的多态继承头文件的修改版，输出数据到文件，//可以按照书上的方法进行修改#ifndef FILEEMP_H#define FILEEMP_H#include<iostream>#include<string>#include<fstream>using std::string;using namespace std;enum classkin { Employee, Manager, Fink, Highfink };class abstr_emp{private:string fname;string lname;string job;public:abstr_emp() :fname("No name"), lname("no name "), job("no job") {};abstr_emp(const string&fn, const string&ln, const string &j) :fname(fn), lname(ln), job(j) {};virtual void ShowAll()const;virtual void SetAll();virtual void writeall(ofstream &fo);//写入到文件的虚函数，又是这里出现无法识别的外部命令virtual void getall(ifstream &fi);//从文件中读取的虚函数friend std::ostream&operator<<(std::ostream &os, const abstr_emp&e);virtual ~abstr_emp() = 0 {};//这里少了{}会报错，链接错误一大堆};class employee :public abstr_emp{public:employee(const string &fn, const string&ln, const string&j) :abstr_emp(fn, ln, j) {};employee() :abstr_emp() {};virtual void ShowAll()const { abstr_emp::ShowAll(); };virtual void SetAll() { abstr_emp::SetAll(); };void writeall(std::ofstream &fo);//写入到文件的虚函数 void getall(std::ifstream &fi);//从文件中读取的虚函数};class manager :virtual public abstr_emp{public:manager() :abstr_emp(), inchargeof(0) {};manager(const string &fn, const string &ln,const string &j, int ico = 0) :abstr_emp(fn, ln, j), inchargeof(ico) {};manager(const abstr_emp&e, int ico) :abstr_emp(e), inchargeof(ico) {};manager(const manager&m);virtual void ShowAll()const;virtual void SetAll(); void writeall(std::ofstream &fo);//写入到文件的虚函数 void getall(std::ifstream &fi);//从文件中读取的虚函数protected:int InChargeOf()const { return inchargeof; }//outut methodint &InChargeOf() { return inchargeof; }//input methodvoid FileChangeOf(std::ofstream &fou)const { fou << inchargeof << "\t"; }void FileChangeOf(std::ifstream&fin) { fin >> inchargeof; }private:int inchargeof;};class fink :virtual public abstr_emp{private:string reportsto;protected:const string ReportsTo()const { return reportsto; }string &ReportsTo() { return reportsto; }void FileReportsTo(std::ofstream &fou) {fou << reportsto;}void FileReportsTo(std::ifstream&fin) { fin >> reportsto; }public:fink() :abstr_emp(), reportsto("null") {};fink(const string &fn, const string &ln,const string &j, const string &rpo) :abstr_emp(fn, ln, j), reportsto(rpo) {};fink(const abstr_emp&e, const string &rpo) :abstr_emp(e), reportsto(rpo) {};fink(const fink&e);virtual void ShowAll()const;virtual void SetAll(); void writeall(std::ofstream &fo);//写入到文件的虚函数 void getall(std::ifstream &fi);//从文件中读取的虚函数};class highfink :public manager, public fink{public:highfink() {};//显式调用基类构造函数highfink(const string &fn, const string &ln,const string &j, const string &rpo, int ico):abstr_emp(fn, ln, j), fink(fn, ln, j, rpo), manager(fn, ln, j, ico) {};highfink(const abstr_emp&e, const string &rpo, int ico):abstr_emp(e), fink(e, rpo), manager(e, ico) {};highfink(const fink &f, int ico):abstr_emp(f), fink(f), manager(f, ico) {};highfink(const manager &m, const string &rpo):abstr_emp(m), manager(m), fink(m, rpo) {};highfink(const highfink&h):abstr_emp(h), manager(h), fink(h) {};virtual void ShowAll()const;virtual void SetAll(); void writeall(std::ofstream &fo);//写入到文件的虚函数void getall(std::ifstream &fi);//从文件中读取的虚函数};#endif // !EMP_H

#include"fileemp.h"using std::cout;using std::endl;using std::cin;//abstr_emp methodsvoid abstr_emp::ShowAll()const{cout <<"\t\t"<< lname << "," << fname << "\t"<< job;}//设置各成员的值void abstr_emp::SetAll(){cout << "Enter frist name: ";std::getline(cin, fname);cout << "Enter last name: ";std::getline(cin, lname);cout << "Job: ";std::getline(cin, job);}//写入数据到文件的方法void abstr_emp::writeall(ofstream &fo){fo<<lname <<endl<< fname <<endl<<job<<endl;}void abstr_emp::getall(ifstream &fi)//书上没有用参数，想想不太可能{std::getline(fi, lname);std::getline(fi, fname);std::getline(fi, job);}//only display namestd::ostream&operator<<(std::ostream &os, const abstr_emp&e){os << "Name: " << e.lname << " , " << e.fname;return os;}//employee的类方法void employee::writeall(std::ofstream &fo){fo << Employee;abstr_emp::writeall(fo);}void employee::getall(std::ifstream &fi){abstr_emp::getall(fi);}//manage methodsmanager::manager(const manager&m) :abstr_emp(m)//copy construction function{inchargeof = m.inchargeof;}void manager::ShowAll()const{cout << endl;abstr_emp::ShowAll();cout <<"\t"<< inchargeof;}void manager::SetAll(){abstr_emp::SetAll();cout << "Enter the inchangeof count: ";cin >> inchargeof;while (cin.get() != '\n')continue;}void manager::writeall(std::ofstream &fou){fou << Manager;abstr_emp::writeall(fou);fou << inchargeof<<endl;}void manager::getall(std::ifstream &fin){abstr_emp::getall(fin);fin >> inchargeof;}//fink methodsfink::fink(const fink&e) :abstr_emp(e){reportsto = e.reportsto;}void fink::ShowAll()const{cout << endl;abstr_emp::ShowAll();cout << "\t" << reportsto;}void fink::SetAll(){cout << "Enter the reportsto: ";std::getline(cin, reportsto);while (cin.get() != '\n')continue;}void fink::writeall(std::ofstream &fou){fou << Fink;abstr_emp::writeall(fou);fou << reportsto<<endl;}void fink::getall(std::ifstream &fin){abstr_emp::getall(fin);std::getline(fin,reportsto);}//highlink methodsvoid highfink::ShowAll()const{cout << endl;abstr_emp::ShowAll();//使用直接基类的保护方法进行输出cout<<"\t"<< manager::InChargeOf();cout<<"\t" << fink::ReportsTo()<<endl;}void highfink::SetAll(){abstr_emp::SetAll();string temp;//这里要弄好一点，不然会设置基类两次，也可以自己int tem;cout << "Enter the inchangeof count: ";//用的是书上那个保护方法，返回引用就可以対值修改cin >> tem;cin.get();//处理换行符cout << "Enter the reportsto: ";std::getline(cin, temp);ReportsTo() = temp;InChargeOf() = tem;}void highfink::writeall(std::ofstream &fou){fou << Highfink;abstr_emp::writeall(fou);manager::FileChangeOf(fou);fink::FileReportsTo(fou);}void highfink::getall(std::ifstream &fin){abstr_emp::getall(fin);manager::FileChangeOf(fin);fink::FileReportsTo(fin);}

c++ Primer Plus（习题17.7)

//大大的填空题//参考了别人的，才发现自己理解错了#include<iostream>#include<fstream>#include<algorithm>#include<string>#include<vector>#include<iterator>void ShowStr(const std::string&s) { std::cout << s << std::endl; }void GetStrs(std::ifstream&fi, std::vector<std::string>&s);class Store{private:std::ofstream&fou;public:Store(std::ofstream&os) :fou(os) {};void operator()(const std::string&s){size_t len = s.size();//size的返回类型,len存储字符串的长度fou.write((char*)&len, sizeof(std::size_t));//先存储长度，书上的用意很明显//这样写是先把字符串的长度len长度信息复制到相关联的文件中fou.write(s.data(), len);//这里是指定字符串的字符数，把字字符串不包括'\0'写入文件}};int main(){using namespace std;vector<string>vostr;string temp;cout << "Enter strings(empty line to quit):\n";while (getline(cin, temp) && temp[0] != '\0')vostr.push_back(temp);cout << "Here is your input.\n";for_each(vostr.begin(), vostr.end(), ShowStr);ofstream fout("string.dat", ios_base::out | ios_base::binary);for_each(vostr.begin(), vostr.end(), Store(fout));fout.close();vector<string>vistr;ifstream fin("string.dat", ios_base::in | ios_base::binary);if (!fin.is_open()){cerr << "Could not open file for input.\n";exit(EXIT_FAILURE);}GetStrs(fin, vistr);cout << "\nHere are the strings read from the file:\n";for_each(vostr.begin(), vostr.end(), ShowStr);return 0;}void GetStrs(std::ifstream&fi, std::vector<std::string>&ve){size_t len;//使用read来获取长度，这个方法很赞while (fi.read((char *)&len, sizeof(size_t))){//这里要知道循环条件就是字符数char *st = new char[len];fi.read(st, len);//len按我的理解就是每个字符所占据的二进制位数st[len + 1] = '\0';//由于没有存储空字符，所以这里人为加ve.push_back(st);}}