[C++ Primer Plus] 第4章、复合类型(二)课后习题

1.编写一个 c++ 程序,如下述输出示例所示的那样请求并显示信息 :

What is your first name? Betty Sue
What is your last name? Yewe
What letter grade do you deserve? B
What is your age? 22
Name : Yewe, Betty Sue
Grade : C
Age: 22

 1 #include<iostream>
 2 using namespace std;
 3 
 4 void main() {
 5     char first_name[30], last_name[30];
 6     char grade;
 7     int age;
 8     cout <<"what is your first name?";
 9     gets_s(first_name);//cin.getline(first, 20); 
10     cout << "what is your last name?";
11     gets_s(last_name);
12     cout << "what letter grade do you deserve?";
13     cin >> grade;
14     cout << "what is your age?";
15     cin >> age;
16 
17     cout << "Name:" << last_name << "," << first_name << endl;
18     cout << "Grade:" << char (grade + 1) << endl;
19     cout << "Age:" << age << endl;
20 
21     system("pause");
22 }

2 . 修改程序淸单 4.4, 使用 C+ + string 类而不是 char数组

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 
 5 void main() {
 6     string name;
 7     string dessert;
 8 
 9     cout << "What's your name?" << endl;
10     getline(cin, name); //读取用户输入的一行字符给name
11     cout << "What's your favorate dessert?" << endl;
12     getline(cin, dessert);
13     cout << "I have some delicious " << dessert << " for you." << endl;
14     system("pause");
15 }

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來,并存储和显示组合结果。请使用 char 数组和头义件 cstring 中的函数。下面是该程序运行时的情形:

Enter your first name : Flip
Enter your last name : Fleming
Here's the information in a single string :Fleming, Flip

 1 #include<iostream>
 2 using namespace std;
 3 
 4 void main() {
 5     char first[20],last[20];
 6 
 7     cout << "Enter your first name :";
 8     cin >> first;
 9     cout << "Enter your last name :";
10     cin >> last;
11     cout << "Here's the information in a single string :" << last << "," << first << endl;
12     system("pause");
13 }

4.编写一个程序,它要求用户首先输入其名,再输入其姓;然后程序使用一个逗号和空格将姓和名组合起来,并存储和显示组合结果。请使用string类和头文件string中的函数。下面是程序运行时的情形:

Enter your first name: Flip

Enter your last name: Fleming

Here's the information in a single string: Fleming, Flip

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 
 5 void main() {
 6     string first,last;
 7 
 8     cout << "Enter your first name :";
 9     cin >> first;
10     cout << "Enter your last name :";
11     cin >> last;
12     cout << "Here's the information in a single string :" << last << "," << first << endl;
13     system("pause");
14 }

5.结构CandyBar包含3个成员。第一个成员存储了糖块的品牌;第二个成员存储糖块的重量(可以有小数);第三个成员存储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。初始化应在声明snack时进行。最后,程序显示snack变量的内容。

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 
 5 struct CandyBar
 6 {
 7     char kind[30];
 8     double weight;
 9     int energy;
10 };
11 
12 void main() {
13     CandyBar snack = { "Mocha Munch",2.3,350};
14 
15     cout << snack.kind<<endl;
16     cout << snack.weight << endl;
17     cout << snack.energy<< endl;
18     system("pause");
19 }

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

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 
 5 struct CandyBar
 6 {
 7     char kind[30];
 8     double weight;
 9     int energy;
10 };
11 
12 void main() {
13     CandyBar snack[3] = {   {"Mocha Munch",2.3,350},
14                             {"wu can rou",2.5,550},
15                             {"qi cai hong",1.5,150 } };
16 
17     cout << snack[0].kind<<"," << snack[0].weight << "," << snack[0].energy <<endl;
18     cout << snack[1].kind << "," << snack[1].weight << "," << snack[1].energy << endl;
19     cout << snack[2].kind << "," << snack[2].weight << "," << snack[2].energy << endl;
20     system("pause");
21 }

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

● 披萨饼公司的名称,可以由多个单词组成。

● 披萨饼的直径。

● 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(或它的方法)和cout。

 1 #include<iostream>
 2 using namespace std;
 3 
 4 struct Pizza
 5 {
 6     char company[30];
 7     double diameter;
 8     double weight;
 9 };
10 
11 void main() {
12     int flag = 1;
13     while (flag)
14     {
15         Pizza p;
16         cout << "请输入公司名:";
17         cin.getline(p.company,30);
18         cout << "请输入披萨直径:";
19         cin >> p.diameter;
20         cout << "请输入披萨重量:";
21         cin >> p.weight;
22         cout << "公司名:" << p.company << ",披萨直径:" << p.diameter << ",披萨重量:" << p.weight << endl;
23 
24         cout << "-----------------------------------------------------------------" << endl;
25         cout << "输入数字0退出,输入其他数字继续:";
26         cin >> flag;
27         cin.get();
28     }
29     //system("pause");
30 }

8.完成编程练习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,让程序在请求输入比萨饼公司名称之前输入比萨饼的直径。

 1 #include<iostream>
 2 #include<string>
 3 using namespace std;
 4 
 5 struct Pizza
 6 {
 7     char company[30];
 8     double diameter;
 9     double weight;
10 };
11 
12 void main() {
13     int flag = 1;
14     while (flag)
15     {
16         Pizza *p=new Pizza;
17         cout << "请输入披萨直径:";
18         cin >> (*p).diameter;
19         cin.get();//读取掉换行符
20         cout << "请输入公司名:";
21         cin.getline((*p).company,30);
22         cout << "请输入披萨重量:";
23         cin >> (*p).weight;
24         cout << "公司名:" << (*p).company << ",披萨直径:" << (*p).diameter << ",披萨重量:" << (*p).weight << endl;
25         delete p;
26 
27         cout << "-----------------------------------------------------------------" << endl;
28         cout << "输入数字0退出,输入其他数字继续:";
29         cin >> flag;
30         cin.get();
31     }
32     //system("pause");
33 }

注意:使用new分配内存之后一定要记得delete

9.完成编程练习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。

 1 #include<iostream>
 2 using namespace std;
 3 
 4 struct CandyBar
 5 {
 6     char kind[30];
 7     double weight;
 8     int energy;
 9 };
10 
11 void main() {
12     CandyBar *p = new CandyBar;
13     *p = { "Mocha Munch",2.3,350 };
14     *(p + 1) = {"wu can rou", 2.5, 550};
15     *(p + 2) = { "qi cai hong",1.5,150 };
16 
17     cout << p[0].kind << "," << p[0].weight << "," << p[0].energy << endl;
18     cout << (*(p + 1)).kind << "," << (*(p + 1)).weight << "," << (*(p + 1)).energy << endl;
19     cout << (p + 2)->kind << "," << (p + 2)->weight << "," << (p + 2)->energy << endl;
20 
21     delete p;
22     system("pause");
23 }

10.编写一个程序,让用户输入三次40码跑的成绩(如果您愿意,也可让用户输入40米跑的成绩),并显示次数和平均成绩。请使用一个array对象来存储数据(如果编译不支持array类,请使用数组)。

 1 #include<iostream>
 2 #include<array>
 3 using namespace std;
 4 
 5 void main() {
 6     array<double, 3> a;
 7     cout << "请输入三次百米跑的成绩。" << endl;
 8     cout << "请输入第一次的成绩(秒):";
 9     cin >> a[0];
10     cout << "请输入第二次的成绩(秒):";
11     cin >> a[1];
12     cout << "请输入第三次的成绩(秒):";
13     cin >> a[2];
14 
15     cout << "您3次的成绩分别为:" << a[0] << "秒," << a[1] << "秒," << a[2] << "秒。"<<endl;
16     cout << "平均成绩为:" << (a[0] + a[1] + a[2]) / 3.0 << "秒," << endl;
17     
18     system("pause");
19 }

原文地址:https://www.cnblogs.com/little-monkey/p/7488416.html