C++ Primer Plus 学习笔记 第四章 04编程练习

1.
#include<iostream>

int main()
{
using namespace std;

cout<<"What is your first name? ";
char firstname[20];
cin.getline(firstname,20);
cout<<"What is your last name? ";
char lastname[20];
cin.getline(lastname,20);
char grade;
cout<<"What letter grade do you deserve? ";
cin>>grade;
int age;
cout<<"What is your age? ";
cin>>age;

cout<<"Name: "<<lastname<<", "<<firstname<<endl;
cout<<"Grade: "<<(char)(grade+1)<<endl;//向下调整成绩，如果强制转换类型，输出会变成67
cout<<"Age: "<<age<<endl;
return 0;
}
2.
#include<iostream>
#include<string>
#include<cstring>
int main()
{
using namespace std;
//const int ArSize = 20;
string name;//char name[ArSize];
string dessert;//char dessert[ArSize];

cout << "Enter your name:\n";
getline(cin,name);
//cin.getline(name,ArSize);
cout << "Enter your favorite dessert:\n";
getline(cin,dessert);
//cin.getline(dessert,ArSize);
cout <<"I have some delicious "<<dessert;
cout <<"for you, "<<name<<endl;
return 0;
}
3.
#include<iostream>
#include<cstring>

int main()
{
using namespace std;

cout<<"Enter your first name: ";
char firstname[20];
cin>>firstname;
cout<<"Enter your last name: ";
char lastname[20];
cin>>lastname;
char name[40];
char a[]=", ";
strcpy(name,lastname);
strcat(name,a);
strcat(name,firstname);

cout<<"Here's the information in a single string："<<name<<endl;
return 0;
}
4.
#include<iostream>
#include<string>

int main()
{
using namespace std;

cout<<"Enter your first name: ";
string firstname;
cin>>firstname;
cout<<"Enter your last name: ";
string lastname;
cin>>lastname;
string name;
string a=", ";
name = lastname + a + firstname;

cout<<"Here's the information in a single string："<<name<<endl;
return 0;
}
5.
#include<iostream>
struct CandyBar
{
char kind[20];
float weight;
int kaluli;
};

int main()
{
using namespace std;
CandyBar snack =
{
"Mocha Munch",
2.3,
350
};
cout<<"糖块的品牌为："<<snack.kind<<endl;
cout<<"糖块的重量为："<<snack.weight<<endl;
cout<<"糖块的卡路里含量为："<<snack.kaluli<<endl;
return 0;
}
6.
#include<iostream>
struct CandyBar
{
char kind[20];
float weight;
int kaluli;
};

int main()
{
using namespace std;

CandyBar shuzu[3] =
{
{"Bambi",0.5,3},
{"Bambi",0.5,3},
{"Bambi",0.5,3}
};

cout<<shuzu[0].kind<<" "<<shuzu[0].weight<<" "<<shuzu[0].kaluli<<endl;
cout<<shuzu[1].kind<<" "<<shuzu[1].weight<<" "<<shuzu[1].kaluli<<
4000
;endl;
cout<<shuzu[2].kind<<" "<<shuzu[2].weight<<" "<<shuzu[2].kaluli<<endl;

return 0;
}
7.
#include<iostream>
#include<cstring>
#include<string>
struct Piza
{
char name[20];//公司名称
double zhijing;//直径
float weight;//重量
};

int main()
{
using namespace std;

Piza piza;
cout<<"请输入公司名称";
cin.getline(piza.name,20);
cout<<"请输入披萨的直径";
cin>>piza.zhijing;
cout<<"请输入披萨的重量";
cin>>piza.weight;

cout<<"公司名称："<<piza.name<<endl;
cout<<"直径："<<piza.zhijing<<endl;
cout<<"重量："<<piza.weight<<endl;
return 0;
}
8.
#include<iostream>
#include<cstring>
#include<string>
struct Piza
{
char name[20];//公司名称
double zhijing;//直径
float weight;//重量
};

int main()
{
using namespace std;

Piza * piza = new Piza;//使用new为结构体分配内存。

cout<<"请输入披萨的直径";
cin>>piza->zhijing;
cin.get();
/*cin读取数字时，将回车键生成的换行符留在了队列中，再使用cin.getline(),将会认为是空行，使用cin.get()解决。*/
cout<<"请输入公司名称";
cin.getline(piza->name,20);
cout<<"请输入披萨的重量";
cin>>piza->weight;

cout<<"公司名称："<<piza->name<<endl;
cout<<"直径："<<piza->zhijing<<endl;
cout<<"重量："<<piza->weight<<endl;
return 0;
}
9.
#include<iostream>
#include<string>
#include<cstring>
using namespace std;
//如果要在main函数外面使用string，把名称空间放在mian函数外面
struct CandyBar
{
string kind;
float weight;
int kaluli;
};

int main()
{

CandyBar * shuzu = new CandyBar [3];
shuzu[0].kind="Bambi";//如果结构体中kind的类型为char数组，这里会报错const char和char
shuzu->weight=3.3;
shuzu->kaluli=55;

cout<<shuzu[0].kind<<" "<<shuzu[0].weight<<" "<<shuzu[0].kaluli<<endl;
return 0;
}
10.
#include<iostream>
int main()
{
using namespace std;

//array<double,3> arr;不能用array
double arr[3];
cout<<"请输入第一次40米跑的成绩(s):";
cin>>arr[0];
cout<<"请输入第二次40米跑的成绩(s):";
cin>>arr[1];
cout<<"请输入第三次40米跑的成绩(s):";
cin>>arr[2];

double anunal=(arr[1]+arr[2]+arr[3])/3;
cout<<"平均成绩为："<<anunal<<endl;
return 0;
}