C++PrimerPlus中文第六版第4章编程练习答案

1、

#include<iostream>
using namespace std;

const int NameSize = 20;

struct stu
{
    char firstName[NameSize];
    char lastName[NameSize];
    char grade;
    int age;
};

int main()
{
    stu s;
    cout << "What is your first name? ";
    cin.getline(s.firstName, NameSize);
    cout << "What is your last name? ";
    cin.getline(s.lastName, NameSize);
    cout << "What letter grade do you deserve? ";
    cin >> s.grade;
    cout << "What is your age? ";
    cin >> s.age;

    cout << "Name: " << s.lastName << ", " << s.firstName << endl;
    cout << "Grade: " << char(s.grade + 1) << endl;
    cout << "Age: " << s.age;

}

2、

#include<iostream>
#include<cstring>
#include<string>
using namespace std;

int main()
{
    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 << " for you, " << name << endl;
}

3、

#include<iostream>
#include<cstring>
using namespace std;

const int NameSize = 10;
const int FullNameSize = 20;

struct person
{
    char firstName[NameSize];
    char lastName[NameSize];
    char fullName[FullNameSize] = "";
};

#pragma warning(disable:4996);
int main()
{
    person p;
    cout << "Enter your first name: ";
    cin >> p.firstName;
    cout << "Enter your last name: ";
    cin >> p.lastName;
    strcat(p.fullName, p.lastName);
    strcat(p.fullName, ", ");
    strcat(p.fullName, p.firstName);
    cout << "Here's the information in a single string: " << p.fullName << endl;
}

4、

#include<iostream>
#include<string>
using namespace std;

struct person
{
    string firstName;
    string lastName;
    string fullName;
};

int main()
{
    person p;
    cout << "Enter your first name:\n";
    getline(cin, p.firstName);
    cout << "Enter your last name:\n";
    getline(cin, p.lastName);
    p.fullName = p.lastName + ", " + p.firstName;
    cout << "Here's the information in a single string: " << p.fullName << endl;
}

5、

#include<iostream>
using namespace std;

struct CandyBar
{
    string brand;
    float weight;
    int calorie;
};

void printCandy(CandyBar);

int main()
{
    CandyBar snack = { "Mocha Munch", 2.3, 350 };
    printCandy(snack);
}

void printCandy(CandyBar c)
{
    cout << "Brand: " << c.brand << ", weight: " << c.weight << ", enrgy: " << c.calorie << endl;
}

6、

#include<iostream>
using namespace std;

struct CandyBar
{
    string brand;
    float weight;
    int calorie;
};

void printCandy(CandyBar);
void printCandy(CandyBar*, int);

int main()
{
    CandyBar snack[3] = { {"Mocha Munch", 2.3, 350}, {"White Rabbit", 5.5, 240}, {"Alpenliebe", 4.8, 220} };
    printCandy(snack, 3);
}

void printCandy(CandyBar c)
{
    cout << "Brand: " << c.brand << ", weight: " << c.weight << ", enrgy: " << c.calorie << endl;
}

void printCandy(CandyBar* c, int len)
{
    for (int i = 0; i < len; i++)
    {
        printCandy(*(c + i));
    }
}

7、

#include<iostream>
#include<string>
using namespace std;

struct PizzaBar
{
    string corporation;
    float diameter;
    float weight;
};

void inPizza(PizzaBar*);
void printPizza(PizzaBar);

int main()
{
    PizzaBar p;
    inPizza(&p);
    printPizza(p);
}

void inPizza(PizzaBar* p)
{
    cout << "Enter the corporation: ";
    getline(cin, p->corporation);
    cout << "Enter the diameter: ";
    cin >> p->diameter;
    cout << "Enter the weight: ";
    cin >> p->weight;
}

void printPizza(PizzaBar p)
{
    cout << "Corporation: " << p.corporation << ", diameter: " << p.diameter << ", weight: " << p.weight << endl;
}

8、

#include<iostream>
#include<string>
using namespace std;

struct PizzaBar
{
    string corporation;//公司名称
    float diameter;//直径
    float weight;//重量
};

void inPizza(PizzaBar*);
void printPizza(PizzaBar);

int main()
{
    PizzaBar* p = new PizzaBar;
    inPizza(p);
    printPizza(*p);
}

void inPizza(PizzaBar* p)
{
    cout << "Enter the diameter: ";
    cin >> p->diameter;
    cout << "Enter the corporation: ";
    cin.get();//由于输入直径的时候留下了一个换行符'\n'在输入流中，所以此时需要把这个换行符去掉
    getline(cin, p->corporation);
    cout << "Enter the weight: ";
    cin >> p->weight;
}

void printPizza(PizzaBar p)
{
    cout << "Corporation: " << p.corporation << ", diameter: " << p.diameter << ", weight: " << p.weight << endl;
}

9、

#include<iostream>
using namespace std;

struct CandyBar
{
    string brand;
    float weight;
    int calorie;
};

void printCandy(CandyBar);
void printCandy(CandyBar*, int);

int main()
{
    CandyBar* snack = new CandyBar[3];
    snack[0] = { "Mocha Munch", 2.3, 350 };
    snack[1] = { "White Rabbit", 5.5, 240 };
    snack[2] = { "Alpenliebe", 4.8, 220 };
    printCandy(snack, 3);
}

void printCandy(CandyBar c)
{
    cout << "Brand: " << c.brand << ", weight: " << c.weight << ", enrgy: " << c.calorie << endl;
}

void printCandy(CandyBar* c, int len)
{
    for (int i = 0; i < len; i++)
    {
        printCandy(*(c + i));
    }
}

10、

#include<iostream>
#include<array>
using namespace std;

int main()
{
    const int N = 3;
    array<double, N> time;
    for (int i = 0; i < N; i++)
    {
        cout << "Enter the " << i+1 << "st seconds:";
        cin >> time[i];
    }
    double ave = (time[0] + time[1] + time[2]) / 3;
    cout << "Average seconds: "<<ave << endl;
}