c++ Primer Plus（第六版）第六章习题，写代码之路

c++ Primer Plus（习题6.1)

//获取输入，小写变成大写，大写变小写，一个函数的应用#include<iostream>#include<cctype>int main(){using namespace std;char ch;cout << "Enter a string,put @ to exit:\n";while (cin.get(ch)&&ch != '@'){if (islower(ch))//判断是否为小写ch = toupper(ch);//变成大写elsech = tolower(ch);cout << ch;}cout << "\nBye!\n";return 0;}

c++ Primer Plus（习题6.2）

//输入double值10个，直到输入非数字//并计算平均值和超过平均值的个数#include<iostream>int main(){using std::cout;using std::endl;using std::cin;double d[10];int i=0;double num = 0;int count=0;cout << "Enter 10 double value: \n";while (cin >> d[i] && i < 10){num += d[i];i++;}double average = num / i;cout << "According to you input,the average is: " << average << endl;while (i>0){if (d[i] > average)count++;i--;}cout << "The number of pass the average is : " << count << endl;cout << "Bye!\n";return 0;}

c++ Primer Plus（习题6.3)

//一个菜单的程序，显示内容自己设计#include<iostream>int main(){using std::cout;using std::cin;using std::endl;cout << "Please enter one of the following choose: \n"<< "c) carnivore                p)planist\n"<< "t) tree                     g)game\n"<< "q) exit\n";char choose;while (cin >> choose&&choose != 'q'){switch (choose){case 'c':cout << "Cat is a dog.\n"; break;case'p':cout << "Planet is a plant.\n"; break;case't':cout << "A map is a tree.\n"; break;case'g':cout << "Game is another game.\n"; break;default:cout << "Please a c,p,t,g,or q: "; break;}cout << "\nPlease enter one of the following choose: \n"<< "c) carnivore                p)planist\n"<< "t) tree                     g)game\n"<< "q) exit\n";}cout << "Bye!\n";return 0;}

c++ Primer Plus（习题6.4)

//BOP的成员名字问题，一个结构，，根据选项下来选择怎么输出//#include<iostream>using namespace std;const int strsize = 20;//Benevolent Order of Programmers name structurestruct bop {char fullname[strsize];   //real namechar title[strsize];//job titlechar bopname[strsize];//secret BOP nameint preference;//0=fullname,1=title,2=bopname};void showmenu();//显示菜单void showname(bop *n);//显示全名的，其他类似，这里是按指针传递参数的void showtitles(bop *n);//void showbop(bop (&n)[5]);void showpre(bop *n);int main(){bop b[5]={//结构数组一定要用常量创建，外面声明一个const int size=5不行{"Wimp Macho","title 1","Mouth",0},{"Raki Rhodes","title 2","Mi",2},{"Celia Laiter","title 3","Wow",1},{"Hoppy Hipman","title 4","Lol",1},{"Pat Hand","title 5","Rxh",2}};char choose;showmenu();while (cin >> choose&&choose != 'q'){switch (choose){case'a':showname(&b[0]); break;case'b':showtitles(&b[0]); break;case'c':showbop(b); break;case'd':showpre(&b[0]); break;default:cout << "Please choose rightly:!";break;}showmenu();}cout << "Bye!\n";return 0;}void showmenu(){cout << "\nPlease enter one of the following choices: \n"<< "a. display by name             b. dispaly by title\n"<< "c. display by bopname          d. display by prefence\n"<< "q. exit\n";}void showname(bop *n){for (int i = 0; i < 5; i++)cout<<(n+i)->fullname<<endl;}void showtitles(bop *n){for (int i = 0; i < 5; i++)cout <<n[i].title << endl;}void showbop(bop (&n)[5]){for (int i = 0; i < 5; i++)cout << n[i].bopname << endl;}void showpre(bop *n)//0=fullname,1=title,2=bopname{for (int i = 0; i < 5; i++){if (n[i].preference == 0)cout << n[i].fullname << endl;else if (n[i].preference == 1)cout << n[i].title << endl;else if (n[i].preference == 2)cout << n[i].bopname << endl;elsecout << "Error preference!\n";}}

c++ Primer Plus（习题6.5)

//典型的税率问题，用用判断就ok了//数学不怎么好的人会弄错，偶就是#include<iostream>const int money_1 = 5000;//为了方便以后调整const int money_2 = 15000;const int money_3= 35000;const double tax_1 = 0.1;const double tax_2 = 0.15;const double tax_3 = 0.2;int main(){using namespace std;double income;cout << "Enter your income: ";while (cin >> income && income>0){double taxs = 0;cout << "Pay for the taxs: ";if (income <=money_1)//小于5000cout << taxs << " Remain:  " << income - taxs << endl;else if (income <=money_2)//5000~15000{taxs = (income - money_1)*tax_1;cout << taxs << " Remain:  " << income - taxs << endl;}else if (income <=money_3)//15000~35000{taxs = (income - money_2)*tax_2 + (money_2-money_1)*tax_1;//范围内收的税固定了cout << taxs << " Remain:  " << income - taxs << endl;}else{taxs = (income - money_3)*tax_3 + (money_3- money_2)*tax_2 + (money_2 - money_1)*tax_1;cout << taxs << " Remain:  " << income - taxs << endl;}cout << "Enter your income: ";}cout << "Bye!\n";return 0;}

c++ Primer Plus（习题6.6)

//一个捐钱的结构，谁捐的多，就有成就#include<iostream>struct menbers {char fullname[20];double money;};int main(){using namespace std;int count;cout << "Enter the numbers of menbers: ";cin >> count;cin.get();//数字和字符混合输入，记得要处理换行符menbers *m = new menbers[count];for (int i = 0; i < count; i++){cout << "Enter the #"<<i+1<<"fullname: ";cin.getline(m[i].fullname, 20);cout << "And money: ";cin >> m[i].money;cin.get();}cout << "Grand Patrons:\n";int many = 0;//用来判断是否有这么好心的人for (int i = 0; i < count; i++){if (m[i].money > 10000){cout << m[i].fullname <<"\t"<< m[i].money << endl;many++;}}if (many == 0)cout << "None\n";many = 0;//重置，判断平凡人cout << "Patrons:\n";for (int i = 0; i < count; i++){if (m[i].money<=10000){cout << m[i].fullname << "\t"<< m[i].money << endl;many++;}}if (many == 0)cout << "None\n";delete[]m;cout << "Bye!\n";return 0;}

c++ Primer Plus（习题6.7)

//每次读取一个单词，判断多少是元音开头，多少辅音\//读取单词可以用数组或string类，简单就好，不要纠结#include<iostream>#include<cstring>#include<cctype>int main(){using namespace std;int vowel = 0;//元音个数int cons = 0;//辅音个数int others = 0;char q[20];cout << "Please enter words(q to exit): ";cin >> q;while (strcmp(q,"q")){if(isalpha(q[0]))switch (q[0]){case 'a':case 'A':case'e':case'E':case'i':case'I':case'o':case'O':case'u':case'U':vowel++; break;default:cons++; break;}else others++;cin >> q;}cout << vowel << " words beginning with vowels.\n"<< cons << " words beginning with consonants.\n"<< others << " others.\n";cout << "Bye!\n";return 0;}

c++ Primer Plus（习题6.8)

//从文件中读字符，这里会显示文件内容//文件自己提供#include<fstream>#include<iostream>#include<cstdlib>int main(){using namespace std;ifstream read_in;//建立一个文件流对象char filename[10];char ch;int num = 0;cout << "Enter the file name: ";cin.getline(filename,10);read_in.open(filename);if (!read_in.is_open()){cout << "Can't open the file " << filename << endl;cout << "Program terminating!\n";exit(EXIT_FAILURE);}read_in.get(ch);while (read_in.good()){cout << ch;num++;read_in.get(ch);}if (read_in.eof())cout << "End of file reached!\n";cout << "The file " << filename << " contains " << num << " characters.\n";read_in.close();cout << "Bye!\n";return 0;}

c++ Primer Plus（习题6.9)

//和第六题一样的，不过是从文件中读取数据，并且显示#include<fstream>#include<iostream>#include<cstdlib>int main(){using namespace std;ifstream money;char filename[10];char ch;cout << "Enter the file name: ";cin.getline(filename, 10);money.open(filename);if (!money.is_open()){cout << "Can't open the file " << filename << endl;cout << "Program terminating!\n";exit(EXIT_FAILURE);}int num;money >> num;cout << num;money.get(ch);while (money.good()){cout << ch;money.get(ch);//实际上可以用结构体的，这里偷了一下懒}if (money.eof())cout << "\nEnd of file reached!\n";money.close();cout << "Bye!\n";return 0;}