1
編寫一個C++程序,如下述輸出示例所示的那樣請求並顯示信息:
注意,該程序應該接受的名字包含多個單詞。另外,程序將向下調整成績,即向上調一個字母。假設用戶請求A、B或C,所以不必擔心D和F之間的空檔。
#include <iostream>
#include <string>
using namespace std;
struct people{
string first_name;
string last_name;
char grade;
int age;
};
int show_people(struct people p)
{
cout<<"**********************************************\n";
cout<<"Name: "<<p.last_name<<", "<<p.first_name<<"\n";
cout<<"Grade: "<<p.grade<<"\n";
cout<<"Age: "<<p.age<<endl;
return 0;
}
int main()
{
struct people p1;
cout<<"What is your first name? ";
getline(cin, p1.first_name);
cout<<"What is your last name? ";
getline(cin, p1.last_name);
cout<<"What letter grade do you deserve? ";
cin>>p1.grade;
p1.grade = p1.grade + 1;
cout<<"What is your age? ";
cin>>p1.age;
show_people(p1);
return 0;
}
2
修改程序清單4.4,使用C++ string類而不是char數組。
#include <iostream>
#include <string>
int main()
{
using namespace std;
string name, dessert;
cout<<"Enter your name:\n";
getline(cin, name);
cout<<"Enter your favorite dessert:\n";
getline(cin, dessert);
cout<<"I have some delicious "<<dessert;
cout<<" for you, "<<name<<".\n";
return 0;
}
下圖爲程序運行結果:
3
編寫一個程序,它要求用戶首先輸入其名,然後輸入其姓;然後程序使用一個逗號和空格將姓和名組合起來,並存儲和顯示組合結果。請使用char數組和頭文件cstring中的函數。下面是該程序運行時的情形:
#include <iostream>
#include <cstring>
int main()
{
using namespace std;
const int Size = 20;
char first_name[Size], last_name[Size], name[2*Size];
cout<<"Enter your first name: ";
cin.getline(first_name, Size);
cout<<"Enter your last name: ";
cin.getline(last_name, Size);
strcpy(name, last_name);
strcat(name, ", ");
strcat(name, first_name);
cout<<"Here's the information in a single string: "<<name<<endl;
return 0;
}
4
編寫一個程序,它要求用戶首先輸入其名,再輸入其姓;然後程序使用一個逗號和空格將姓和名組合起來,並存儲和顯示組合結果。請使用string對象和頭文件string中的函數。下面是該程序運行時的情形:
#include <iostream>
#include <string>
int main()
{
using namespace std;
string first_name, last_name, name;
cout<<"Enter your first name: ";
getline(cin, first_name);
cout<<"Enter your last name: ";
getline(cin, last_name);
name = first_name + ", " + last_name;
cout<<"Here's the information in a single string: "<<name<<endl;
return 0;
}
5
結構CandyBar包含3個成員。第一個成員存儲了糖塊的品牌;第二個成員存儲糖塊的重量(可以有小數);第三個成員存儲了糖塊的卡路里含量(整數)。請編寫一個程序,聲明這個結構,創建一個名爲snack的CandyBar變量,並將其成員分別初始化爲“Mocha Munch”、2.3和350。初始化應在聲明snack時進行。最後,程序顯示snack變量的內容。
#include <iostream>
#include <string>
using namespace std;
struct CandyBar{
string brand;
double weight;
int calorie;
};
int main()
{
CandyBar snack = {"Mocha Munch", 2.3, 350};
cout<<"Brand: "<<snack.brand<<endl;
cout<<"Weight: "<<snack.weight<<endl;
cout<<"Calorite: "<<snack.calorie<<endl;
return 0;
}
6
結構CandyBar包含3個成員,如編程練習5所示。請編寫一個程序,創建一個包含3個元素的CandyBar數組,並將它們初始化爲所選擇的值,然後顯示每個結構的內容。
#include <iostream>
#include <string>
using namespace std;
struct CandyBar{
string brand;
double weight;
int calorie;
};
int main()
{
CandyBar snack[3] = {
{"Mocha Munch", 2.3, 350},
{"Coca Cola", 1.4, 420},
{"Green Arrow", 2.7, 260}
};
int i;
for(i=0; i<3; i++)
{
cout<<"\nsnack["<<i+1<<"]:\n";
cout<<"Brand: "<<snack[i].brand<<endl;
cout<<"Weight: "<<snack[i].weight<<endl;
cout<<"Calorite: "<<snack[i].calorie<<endl;
}
return 0;
}
7
William Wingate從事比薩餅分析服務。對於每個披薩餅,他都需要記錄下列信息:
- 披薩餅公司的名稱,可以有多個單詞組成。
- 披薩餅的直徑。
- 披薩餅的重量。
設計一個能夠存儲這些信息的結構,並編寫一個使用這種結構變量的程序。程序將請求用戶輸入上述信息,然後顯示這些信息。請使用cin(或它的方法)和cout。
#include <iostream>
const int Size = 50;
struct pizza{
char name[Size];
double diameter;
double weight;
};
int main()
{
using namespace std;
pizza p1;
cout<<"Please input the name of pizza company: ";
cin.getline(p1.name, Size);
cout<<"Please input the diameter of pizza: ";
cin>>p1.diameter;
cout<<"Please input the weight of pizza: ";
cin>>p1.weight;
cout<<"Company: "<<p1.name<<"\n";
cout<<"Diameter: "<<p1.diameter<<"\n";
cout<<"Weight: "<<p1.weight<<"\n";
return 0;
}
以下爲程序運行結果:
8
完成編程練習7,但使用new來爲結構分配內存,而不是聲明一個結構變量。另外,讓程序在請求輸入比薩餅公司名稱之前輸入比薩餅的直徑。
#include <iostream>
const int Size = 50;
struct pizza{
char name[Size];
double diameter;
double weight;
};
int main()
{
using namespace std;
pizza *p1 = new pizza;
cout<<"Please input the diameter of pizza: ";
cin>>p1->diameter;
cin.get();
cout<<"Please input the name of pizza company: ";
cin.getline(p1->name, Size);
cout<<"Please input the weight of pizza: ";
cin>>p1->weight;
cout<<"Company: "<<p1->name<<"\n";
cout<<"Diameter: "<<p1->diameter<<"\n";
cout<<"Weight: "<<p1->weight<<"\n";
delete p1;
return 0;
}
以下爲程序運行結果:
9
完成編程練習6,但使用new來動態分配數組,而不是聲明一個包含3個元素的CandyBar數組。
#include <iostream>
#include <string>
using namespace std;
struct CandyBar{
string brand;
double weight;
int calorie;
};
int main()
{
CandyBar *snack = new CandyBar[3];
snack[0].brand = "Mocha Munch";
snack[0].weight = 2.3;
snack[0].calorie = 350;
snack[1].brand = "Caca Cola";
snack[1].weight = 1.4;
snack[1].calorie = 420;
snack[2].brand = "Green Arrow";
snack[2].weight = 2.7;
snack[2].calorie = 260;
int i;
for(i=0; i<3; i++)
{
cout<<"\nsnack["<<i+1<<"]:\n";
cout<<"Brand: "<<snack[i].brand<<endl;
cout<<"Weight: "<<snack[i].weight<<endl;
cout<<"Calorite: "<<snack[i].calorie<<endl;
}
delete [] snack;
return 0;
}
以下爲程序運行結果:
10
編寫一個程序,讓用戶輸入三次40碼跑的成績(如果您願意,也可讓用戶輸入40米跑的成績),並顯示次數和平均成績。請使用一個array對象來存儲數據(如果編譯器不支持array類,請使用數組)。
#include <iostream>
#include <array>
int main()
{
using namespace std;
array<double, 3> time;
int i;
double average, sum = 0;
for(i=0; i<3; i++)
{
cout<<"Please input No."<<i+1<<" time: ";
cin>>time[i];
sum = sum + time[i];
}
average = sum / 3;
for(i=0; i<3; i++)
{
cout<<"Time "<<i+1<<": "<<time[i]<<endl;
}
cout<<"Average = "<<average<<endl;
return 0;
}
以下爲程序運行結果: