1. 编写一个程序，读取键盘输入，直到遇到@符号为止，并回显输入（数字除外），同时将大写字符转换为小写，将小写字符转换为大写（别忘了cctype函数系列）。

 

#include

#include//prototypes for character functions

using namespace std;



int main()

{

    char ch;//定义一个char类型变量

    cout << "Enter the character,and type @"< 大写

         }

         else if (isupper(ch))//当输入的是大写字母时

         {

             ch = tolower(ch);//大写 -> 小写

         }

         cout << ch ;

         cin.get(ch);

        

    }

    system("pause");

    return 0;

}

//Enter the character, and type @

//@

//@

//china

//CHINA

//

//

//CHINA

//china

2. 编写一个程序，最多将10个donation值读入到一个double数组中（如果您愿意，也可使用模板类array）。程序遇到非数字输入时将结束输入，并报告这些数字的平均值以及数组中有多少个数字大于平均值。

#include

#include

using namespace std;



int main()

{

    array donation;//使用array模板定义数组长度为10

    double input;

    int counter = 0;

    double average, sum = 0;

    int bigger = 0;

    //sum ->和 average ->平均值 counter ->元素数 bigger->大于平均值的个数

    cout << "Enter the double numerical:";

    cin >> input;

    while (input != 0 && counter < 10)

    {

         donation[counter++] = input;

         cout << "No." << counter << " Data input to Array." << endl;

         cout << "Enter the double numerical.";

         cin >> input;

    }//通过while循环输入数据，当输入非数字时或超过10个元素时推出循环

    for (int i = 0; i < counter; i++)

    {

         sum += donation[i];//十个数的总和

    }

    average = sum / counter;

    for (int i = 0; i < counter; i++)

    {

         if (donation[i] > average)

             bigger++;

    }//通过遍历计算大于平均值的元素个数

    cout << "The Average is " << average << " and " << bigger;

    cout << " data bigger than average." << endl;

    system("pause");

    return 0;

}



//Enter the double numerical : 10

//No.1 Data input to Array.

//Enter the double numerical.20

//No.2 Data input to Array.

//Enter the double numerical.30

//No.3 Data input to Array.

//Enter the double numerical.40

//No.4 Data input to Array.

//Enter the double numerical.50

//No.5 Data input to Array.

//Enter the double numerical.60

//No.6 Data input to Array.

//Enter the double numerical.70

//No.7 Data input to Array.

//Enter the double numerical.80

//No.8 Data input to Array.

//Enter the double numerical.90

//No.9 Data input to Array.

//Enter the double numerical.100

//No.10 Data input to Array.

//Enter the double numerical.110

//The Average is 55 and 5 data bigger than average.

//请按任意键继续. . .

3. 编写一个菜单驱动程序的雏形。该程序显示一个提供4个选项的菜单——每个选项用一个字母标记。如果用户使用有效选项之外的字母进行响应，程序将提示用户输入一个有效的字母，直到用户这样做为止。然后，该程序使用一条switch语句，根据用户的选择执行一个简单操作。该程序的运行情况如下：

Please enter one of the following choices:

c) carnivore            p) pianist

t) tree                     g) game

f

Please enter a c, p, t, or g: q

Please enter a c, p, t, or g: t

A maple is a tree.

#include

using namespace std;

void showmenu();//showmenu()函数声明



int main()

{

    char choice;

    showmenu();

    cin.get(choice);//显示菜单，并读取用户输入，保存至choice变量中

    while (choice != 'c' && choice != 'p' && choice != 't' && choice != 'g')

    {

         cin.get();

         cout << "Please enter a,c,p,t,or g ";

         cin.get(choice);

    }

    switch (choice)

    {

    case'c':

         break;

    case'p':

         break;

    case't':

         cout << "Asample is a tree." << endl;

    case'g':

         break;

    }

    system("pause");

    return 0;

}



void showmenu()

{

    cout << "Please enter one of the following choice:n";

    cout << "c) carnivore ttt p) pianistn";

    cout << "t) treetttt g)gamen";

}//showmenu()函数只负责菜单传递信息的输出

//Please enter one of the following choice :

//c) carnivore                     p) pianist

//t) tree                          g)game

//f

//Please enter a, c, p, t, or g q

//Please enter a, c, p, t, or g t

//Asample is a tree.

//请按任意键继续. . .

4. 加入Benevolent Order of Programmer后，在BOP大会上，人们便可以通过加入者的真实姓名、头衔或秘密BOP姓名了解他（她）。请编写一个程序，可以使用真实姓名、头衔、秘密姓名或成员偏好来列出成员。编写该程序时，请使用下面的结构：

// Benevolent Order of Programmer name structure

struct bop {

    char fullname[strsize];      // real name

    char title[strsize];              // job title

    char bopname[strsize];     // secret BOP name

    int preference;                  // 0 = fullname, 1 = title, 2 = bopname

};

该程序创建一个由上述结构组成的小型数组，并将其初始化为适当的值。另外，该程序使用一个循环，让用户在下面的选项中进行选择：

a. display by name        b. display by title

c. display by bopname  d. display by preference

q. quit

注意，“display by preference”并不意味着显示成员的偏好，而是意味着根据成员的偏好来列出成员。例如，如果偏好号为1，则选择d将显示程序员的头衔。该程序的运行情况如下：

Benevolent Order Programmer Report

a. display by name        b. display by title

c. display by bopname  d. display by preference

q. quit

Enter your choice: a

Wimp Macho

Raki Rhodes

Celia Laiter

Hoppy Hipman

Pat Hand

Next choice: d

Wimp Macho

Junior Programmer

MIPS

Analyst Trainee

LOOPY

Next choice: q

Bye!

这题不会直接抄答案。

#include

#include

using namespace std;



const int strsize = 40;

const int usersize = 5;



//Benevolent Order of Programmer 姓名结构体

struct bop

{

    char fullname[strsize];//真实姓名

    char title[strsize];//头衔

    char bopname[strsize];//秘密BOP姓名

    int preference;//0 = fullname,1 = title;2 = bopname

};

bop bop_user[usersize] =

{

    {"Wimp Macho","Programmer","MIPS",0},

    {"Raki Rhodes","Junior Programmer",1},

    {"Celia Laiter","","MIPS",2},

    {"Hoppy Hipman","Analyst Trainee","",1},

    {"Pat Hand","","LOOPY",2},

};//定义常量，定义结构体初始化bop数组信息

void showmenu();//showmenu()函数声明

void print_by_name();//打印姓名函数声明

void print_by_pref();//打印偏好函数声明

void print_by_title();//打印头衔函数声明

void print_by_bopname();//打印秘密姓名函数声明

void create_info();



int main()

{

    char choice;

    //create_info();

    showmenu();

    cout << "Enter your choice:";

    cin.get(choice);//显示菜单读取用户输入

    while (choice != 'q')

    {

         switch (choice)

         {

         case 'a':

             print_by_name();

             break;

         case 'b':

             print_by_title();

             break;

         case 'c':

             print_by_bopname();

             break;

         case 'd':

             print_by_pref();

             break;

         default:

             cout << "Please enter character a ,b ,c ,d , or q:" << endl;

         }

         //通过switch语句对应的函数进行显示

         cout << "Next choice:";

         cin.get(choice);

    }

    //将switch语句放在while循环中，可以反复循环给下那个功能

    cout << "Bye!" << endl;

    system("pause");

    return 0;

}

void showmenu()

{

    cout << "a. display by namett b. display by title" << endl;

    cout << "c. display by bopnamett d. display by preference" << endl;

    cout << "q. quit" << endl;

}//显示菜单

void print_by_name()

{

    for (int i = 0; i < usersize; i++)

    {

         if (bop_user[i].fullname == 0)

             break;

         else

             cout << bop_user[i].fullname << endl;

    }

}



void print_by_pref()

{

    for (int i = 0; i < usersize; i++)

    {

         if (bop_user[i].fullname == 0)

             break;

         else

         {

             switch (bop_user[i].preference)

             {

             case 0:

                  cout << bop_user[i].fullname << endl;

                  break;

             case 1:

                  cout << bop_user[i].title << endl;

                  break;

             case 2:

                  cout << bop_user[i].bopname << endl;

                  break;

             }

         }

    }

}





void print_by_title()

{

    for (int i = 0; i < usersize; i++)

    {

         if (bop_user[i].fullname == 0)

             break;

         else

         {

             cout << bop_user[i].title << endl;

             break;

         }

    }

}



void print_by_bopname()

{

    for (int i = 0; i < usersize; i++)

    {

         if (bop_user[i].fullname == 0)

             break;

         else

         {

             cout << bop_user[i].bopname << endl;

             break;

         }

    }

}



void create_info()

{

    for (int i = 0; i < usersize; i++)

    {

         cout << "Enter the user's full name:";

         cin.getline(bop_user[i].fullname, strsize);

         cout << "Enter the user's title:";

         cin.getline(bop_user[i].title, strsize);

         cout << "Enter the user's bopname:";

         cin.getline(bop_user[i].bopname, strsize);

         cout << "Enter the user's preference:";

         cin >> bop_user[i].preference;

         cout << "Next...(f for finished):";

         cin.get();

         if (cin.get() == 'f') break;

    }

}

//a.display by name               b.display by title

//c.display by bopname            d.display by preference

//q.quit

//Enter your choice : a

//Wimp Macho

//Raki Rhodes

//Celia Laiter

//Hoppy Hipman

//Pat Hand

//Next choice : Please enter character a, b, c, d, or q :

//Next choice : d

//Wimp Macho

//Raki Rhodes

//MIPS

//Analyst Trainee

//LOOPY

//Next choice : Please enter character a, b, c, d, or q :

//Next choice : q

//Bye!

//请按任意键继续. . .

5. 在Neutronia王国，货币单位是tvarp，收入所得税的计算方式如下：

5000 tvarps：不收税

5001~15000 tvarps：10%

15001~35000 tvarps：15%

35000 tvarps以上：20%

例如，收入为38000 tvarps 时，所得税为5000*0.00+10000*0.10+20000*0.15+3000*0.20，即4600 tvarps。请编写一个程序，使用循环来要求用户输入收入，并报告所得税。当用户输入负数或非数字时，循环将结束。

 

#include

using namespace std;


int main()

{

    float tax, salary;

    cout << "Please enter your salary:";

    cin >> salary;

    while (salary > 0)

    {

         if (salary < 5000)

         {

             tax = 0;

         }

         else if (salary <= 15000)

         {

             tax = (salary - 5000) * 0.10;

         }

         else if (salary <= 35000)

         {

             tax = 10000 * 0.10 + (salary - 15000) * 0.15;

         }

         else if (salary > 35000)

         {

             tax = 10000 * 0.10 + 20000 * 0.15 + (salary - 30000) * 0.20;

         }

         cout << "Your salary is " << salary << " trarps,and you should pay ";

         cout << tax << " trarps of tax." << endl;

         cout << "Enter your salary:";

         cin >> salary;

    }

    cout << "Bye!" << endl;

    system("pause");

    return 0;

}

//Please enter your salary : 4000

//Your salary is 4000 trarps, and you should pay 0 trarps of tax.

//Enter your salary : 15000

//Your salary is 15000 trarps, and you should pay 1000 trarps of tax.

//Enter your salary : 25000

//Your salary is 25000 trarps, and you should pay 2500 trarps of tax.

//Enter your salary : 40000

//Your salary is 40000 trarps, and you should pay 6000 trarps of tax.

//Enter your salary : 0

//Bye!

//请按任意键继续...

6. 编写一个程序，记录捐助给“维护合法权利团体”的资金。该程序要求用户输入捐赠者数目，然后要求用户输入每一个捐献者的姓名和款项。这些信息被储存在一个动态分配的结构数组中。每个结构有两个成员：用来储存姓名和字符数组（或string对象）和用来存储款项的double成员。读取所有的数据后，程序将显示所有捐款超过10000的捐献者的姓名及其捐款数额。该列表前应包含一个标题，指出下面的捐款者是重要捐款人（Grand Patrons）。然后，程序将列出其他的捐款者，该列表要以Patrons开头。如果某种类型没有捐献者，则程序将打印单词“none”。该程序只显示这两种类别，而不进行排序。

#include

#include

using namespace std;



struct patrons {

    string full_name;

    double fund;

};//捐款人基本信息的结构体

int main()

{

    int patrons_number;

    patrons *ppatrons;

    cout << "How many patrons ? ";

    cin >> patrons_number;

    cin.get();

    ppatrons = new patrons[patrons_number];//建立动态数组

    int id = 0;

    bool empty = true;

    cout << "Starting to input patron's info:";

    while (id < patrons_number)

    {

         cout << "Enter the full name of patrons: ";

         getline(cin, ppatrons[id].full_name);

         cout << "Enter the fuud of " << ppatrons[id].full_name << " : ";

         cin >> ppatrons[id].fund;

         cin.get();

         id++;

         cout << "Continue to input,or press (f) to finished.";

         if (cin.get() == 'f')

             break;

    }//建立捐款人名单

    cout << "Grand Patrons" << endl;

    for (int i = 0; i < patrons_number; i++)

    {

         if (ppatrons[i].fund >= 1000) {

             cout << ppatrons[i].full_name << " : " << ppatrons[i].fund << endl;

             empty = false;

         }

    }

    //查询Grand Patrons名单，如果empty为true，输出NONE

    if (empty)

         cout << "NONE" << endl;

    empty = false;

    cout << "Patrons" << endl;

    for (int i = 0; i < patrons_number; i++)

    {

         if (ppatrons[i].fund < 1000) {

             cout << ppatrons[i].full_name << " : " << ppatrons[i].fund << endl;

         }

    }

    if (empty)

         cout << "NONE" << endl;

    system("pause");

    return 0;

}

//How many patrons ? 2

//Starting to input patron's info:Enter the full name of patrons: LI MING

//Enter the fuud of LI MING : 5000

//Continue to input, or press(f) to finished.

//Enter the full name of patrons : LI HUA

//Enter the fuud of LI HUA : 1000

//Continue to input, or press(f) to finished.f

//Grand Patrons

//LI MING : 5000

//LI HUA : 1000

//Patrons

//请按任意键继续. . .

7. 编写一个程序，它每次读取一个单词，直到用户只输入q。然后，该程序指出有多少个单词以元音打头，有多少个单词以辅音打头，还有多少个单词不属于这两类。为此，方法之一是，使用isalpha()来区分字母和其他字符打头的单词，然后对于通过了isalpha()测试的单词，使用if或switch语句来确定哪些以元音打头。该程序的运行情况如下：

Enter words (q to quit):

The 12 awesome oxen ambled

quietly across 15 meters of lawn. q

5 words beginning with vowels

4 words beginning consotants

2 others

#include

#include

using namespace std;



int main()

{

    char words[40];

    int vowel, consonant, others;

    vowel = consonant = others = 0;

    cout << "Enter words(q to quit):" << endl;

    cin >> words;

    while (strcmp(words, "q") != 0)

    {

         if (!isalpha(words[0]))

         {

             others++;

         }//统计非字母开头的单词

         else {

             switch (words[0])

             {

             case 'a':

             case 'e':

             case 'i':

             case 'o':

             case 'u':

                  vowel++;//统计以元音字母开头的单词

                  break;

             default:

                  consonant++;//统计非元音字母开头的单词

             }

         }

         cin >> words;

    }

    cout << vowel << " words beginning with vowel." << endl;

    cout << consonant << " words beginning with consonants." << endl;

    system("pause");

    return 0;

}

//Enter words(q to quit) :

//The 12 awesome oxen ambled

//quitely across 15 meters of lawn

//q

//5 words beginning with vowel.

//4 words beginning with consonants.

//请按任意键继续. . .

8. 编写一个程序，它打开一个文件，逐个字符地读取该文件，直到到达文件末尾，然后指出该文件中包含多少个字符。

#include

#include

using namespace std;



int main()

{

    ifstream fin;//定义文件输入流

    string file_name;

    cout << "Enter the file name:";

    getline(cin, file_name);

    fin.open(file_name);

    if (!fin.is_open()) {

         cout << "Error to open file." << endl;

         exit(EXIT_FAILURE);

    }

    char read_char;

    int char_counter = 0;

    while (!fin.eof()) {

         fin >> read_char;

         char_counter++;

    }

    cout << "The file " << file_name << " contains " << char_counter << " characters." << endl;

    fin.close();//关闭文件

    system("pause");

    return 0;

}

建立txt文件如下所示：

9. 完成编程练习6，但从文件中读取所需的信息。该文件的第一项应为捐款人数，余下的内容应为成对的行。在每一对中，第一行为捐款人姓名，第二行为捐款数额。即该文件类似于下面：

4

Sam Stone

2000

Freida Flass

100500

Tammy Tubbs

5000

Rich Raptor

55000

#include 

#include 

#include

using namespace std;



struct patrons {

    string full_name;

    double fund;

};

//表示捐款人信息的结构体

int main()

{

    ifstream fin;

    string file_name;

    cout << "Enter the file name:";

    getline(cin, file_name);

    fin.open(file_name);

    if (!fin.is_open())

    {

         cout << "Error to open file:" << endl;

         exit(EXIT_FAILURE);

    }

    int patrons_number;

    patrons *ppatrons;

    int id = 0;

    bool empty = true;



    fin >> patrons_number;

    if (patrons_number <= 0)

    {

         exit(EXIT_FAILURE);

    }

    ppatrons = new patrons[patrons_number];

    fin.get();

    //读取人数，创建动态数组

    while (!fin.eof() && id < patrons_number)

    {

         getline(fin, ppatrons[id].full_name);

         cout << "Read Name: " << ppatrons[id].full_name << endl;

         fin >> ppatrons[id].fund;

         cout << "Read fund: " << ppatrons[id].fund << endl;

         fin.get();

         id++;

    }

    //循环读取捐款人信息，也可以使用for循环

    fin.close();//关闭文件

    cout << "Grand Patrons" << endl;

    for (int i = 0; i < patrons_number; i++)

    {

         if (ppatrons[i].fund >= 10000) {

             cout << ppatrons[i].full_name << " ; " << ppatrons[i].fund << endl;

             empty = false;

         }

    }

   

    if (empty)

    cout << "NONE" << endl;

    empty = false;

    cout << "Patrons" << endl;

    for (int i = 0; i < patrons_number; i++)

    {

         if (ppatrons[i].fund < 10000) {

             cout << ppatrons[i].full_name << " : " << ppatrons[i].fund << endl;

         }

    }

    if (empty) cout << "NONE" << endl;

    system("pause");

    return 0;

}

建立txt文件如下所示：