c++primerplus(第六版)编程题——第4章（复合类型）

 

声明：作者为了调试方便，每一章的程序写在一个工程文件中，每一道编程练习题新建一个独立文件，在主函数中调用,我建议同我一样的初学者可以采用这种方式，调试起来会比较方便。

(具体方式参见第3章模板)

1.编写一个程序，如下述输出示例所示的那样请求显示信息：（注意：该程序应该接受的名字包含多个单词，另外，程序将向下调整成绩，即向上调一个字母。假设用户请求A、B 或C，所以不用担心D和F之间的空档。）

#include <iostream>

#include <string>

#include <cstring>

using namespace std;



void cprimerplus_exercise4_1()

{

    string firstname, lastname;

    char lettergrade;

    int age;

    cout << "What is you first name?";

    getline( cin, firstname);



    cout << "What is your last name?";

    getline(cin ,lastname);



    cout <<  "What letter grade do you deserve?";

    cin >> lettergrade;



    cout << "What is your age?";

    cin >> age;



    cout << "Name:" << lastname << "," << firstname << endl;

    cout << "Grade:"<< char (lettergrade + 1) << endl;

    cout << "Age:" << age << endl;

}

2.修改程序清单4.4，使用C++ string类而不是char数组。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;

void cprimerplus_exercise4_2()

{

    string name;

    string dessert;

    cout << "Enter your name:" << endl;

    getline( cin, name);



    cout << "Enter your favourite dessert:" << endl;

    getline(cin ,dessert);



    cout << "I have some delicious " << dessert << " for you," << name << endl;



}

3.编写一个程序，它要求用户首先输入其名，然后输入其姓；然后程序使用一个逗号和空格将姓和名组合起来，并储存和显示结果。请使用char数组和头文件cstring中的函数。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;

void cprimerplus_exercise4_3()

{

    char firstname[20];

    char lastname[20];

    cout << "Enter your first name:";

    cin.getline( firstname, 20);



    cout << "Enter your last name:";

    cin.getline(lastname, 20);



    cout << "Here is the information in a single string:" << strcat(strcat( firstname,","), lastname ) << endl;

}

4.编写一个程序，它要求用户首先输入其名，然后输入其姓；然后程序使用一个逗号和空格将姓和名组合起来，并储存和显示结果。请使用string对象和头文件string中的函数。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;

void cprimerplus_exercise4_4()

{

    string firstname;

    string lastname;



    cout << "Enter your first name:";

    getline(cin, firstname);



    cout << "Enter your last name:";

    getline(cin, lastname);



    cout << "Here is the information in a single string:"\

        <<lastname + "," + firstname << endl;

}

5.结构CandyBar包含3个成员。第一个成员储存了糖块的品牌；第二个成员储存糖块的重量（可以有小数）；第三个成员储存了糖块的卡路里含量（整数）。请编写一个程序，声明这个结构，创建一个名为snack的CandyBar变量。并将其成员分别初始化为”Mocha Munch”、2.3和350。初始化在声明snack是进行。最后，程序显示变量snack变量的内容。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;

void cprimerplus_exercise4_5()

{

    struct CandyBar

    {

        char name[20];

        double weight;

        int calary;

    };



    CandyBar snack = {

        "Mocha Munch",

        2.3,

        350

    };

    cout << "Name:" << snack.name << endl;

    cout << "Weight:" << snack.weight << endl;

    cout << "calary:" << snack.calary << endl;

}

6.结构CandyBar包含3个成员，如编程5所示，请编写一个程序，创建一个包含3个元素的CandyBar数组，并将他们初始化为所选择的值，然后显示每个结构的内容。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;



void cprimerplus_exercise4_6()

{

    struct CandyBar

    {

        char name[20];

        double weight;

        int calary;

    };



    CandyBar snack[3] = {

        {"Mocha Munch", 2.3, 350},\

        {"Mocha Munch", 2.3, 350},\

        {"Mocha Munch", 2.3, 350},\

    };

    for (int i = 0; i < 3; i++)

    {

        cout << "Name:" << snack[i].name << endl;

        cout << "Weight:" << snack[i].weight << endl;

        cout << "calary:" << snack[i].calary << endl;

        cout << endl;

    }

    

}

7. William Wingate从事披萨饼分析服务。对于每个披萨饼，他都需要记录下列信息：

（1）披萨饼公司的名称，可以有多个单词组成。

（2）披萨饼的直径。

（3）披萨饼的重量。

请设计一个能够储存这些信息的结构，并编写一个使用着这种结构变量的程序。程序将请求用户输入上述信息，然后显示这些信息。请使用cin（或其他方法）和cout。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;



void cprimerplus_exercise4_7()

{

    struct pizzamessage{

        string name;

        double diameter;

        double weight;

    };



    pizzamessage message;

    cout << "Please input the message of pizza!"<<endl;

    cout << "Name:";

    getline( cin, message.name);

    

    cout <<"Diameter:";

    cin >> message.diameter;



    cout << "Weight:";

    cin >> message.weight;



    cout << "the message of the record is:"<< endl;

    cout << "Name:" << message.name;

    cout << "Diameter:" << message.diameter;

    cout << "Weight:" << message.weight;

}

8.完成编程7，但使用new来为结构分配内存，而不是声明一个结构变量。另外，让程序在请求输入披萨饼公司名称之前输入披萨饼的直径。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;



void cprimerplus_exercise4_8()

{

    struct pizzamessage{

        string name;

        double diameter;

        double weight;

    };



    int num;

    cout << "How many pieces of pizzamessage you want to be record?";

    cin >> num;

    cin.get();



    pizzamessage *message = new pizzamessage[num];



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

    {

        cout << "Please input the pizza message of the " << i + 1 << "th record:"<< endl;

        cout << "Name:";

        getline(cin,message[i].name);



        cout <<"Diameter:";

        cin >> message[i].diameter;



        cout << "Weight:";

        cin >>message[i].weight;

        cout << endl;



        cin.get();



    }



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

    {

        cout << "the message of the "<< i+1 << "record is:"<< endl;

        cout << "Name:" << message[i].name << endl;

        cout << "Diameter:" << message[i].diameter << endl;

        cout << "Weight:" << message[i].weight << endl;

        cout << endl;

    }



}

9.完成编程6，但使用new来动态分配数组，而不是声明一个包含3个元素的CandyBar数组。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;



void cprimerplus_exercise4_9()

{

    struct CandyBar

    {

        char name[20];

        double weight;

        int calary;

    };



    cout << "How many do you want to create?";

    int num;

    cin >> num;

    cin.get();



    CandyBar *candies = new CandyBar[num];



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

    {

        cout << "please input the message:" << endl;

        cout << "name:";

        cin >> candies[i].name;



        cout << "weight:";

        cin >> candies[i].weight;



        cout << "calary:";

        cin >> candies[i].calary;

    }

    cout << endl;



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

    {

        cout << "the message:" << endl;

        cout << "name:" << candies[i].name << endl;

        cout << "weight:" << candies[i].weight << endl;

        cout << "calary:" << candies[i].calary << endl;



        cout << endl;

    }

}

10. 编写一个程序，让用户输入三次40码跑的成绩（也可以让用户输入），并显示次数和平均成绩。请使用一个array对象来储存数据（也可以使用数组）。

#include <iostream>

#include <string>

#include <cstring>

using namespace std;



void cprimerplus_exercise4_10()

{

    cout << "How many times do you want to record?"<< endl;

    int num;

    cin >> num;

    

    double * times = new double[num];



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

    {

        cout << i+1 << " th input:" << endl;

        cin >> times[i];

    }



    double sum = 0;

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

    {

        sum +=times[i];

    }



    cout << "you have " << num << "records" << endl;

    cout << " your average score is " << sum / num << endl;

}