9.14. Coding Practice

Q1

Question

Write the cake structure, which has instance variables name, color, diameter, and has_icing.

Example cp_9_AC_1q

#include <iostream>
using namespace std;

// Write your code for the struct cake here.

int main() {
    cake c = { "Mary", "blue", 3.5, false };
}

Answer

Below is one way to implement the program. We declare the cake struct and list the instance variables in order.

Example cp_9_AC_1a

#include <iostream>
using namespace std;

struct cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

int main() {
    cake c = { "Mary", "blue", 3.5, false };
}

Q2

Write the function print_cake_info, which prints the cake's information in the format "This is a color, diameter inch diameter cake with/without icing." If name does not have the value "n/a", print_cake_info prints out "Happy birthdday name! Your cake is color, has a diameter inch diameter, and comes with/without icing."

Example cp_9_AC_2q

#include <iostream>
using namespace std;

struct cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

// Write your code for the print_cake_info function here.

int main() {
    cake c1 = { "n/a", "red", 12.5, true };
    print_cake_info (c1);
    cake c2 = { "Tom", "white", 10, false };
    print_cake_info (c2);
}

Q3

Question

Write the make_cake function, which prompts the user for a name, color, diameter, and whether or not they want icing. The function then returns the cake.

Example cp_9_AC_3q

#include <iostream>
using namespace std;

struct cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void print_cake_info (cake c);

// Write your code for the make_cake function here.

int main() {
    cake input = make_cake ();
    print_cake_info (input);
}

Answer

Below is one way to implement the program. We create a cake for the user, read in the user's input using cin, and return the cake.

Example cp_9_AC_3a

#include <iostream>
using namespace std;

struct cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void print_cake_info (cake c);

cake make_cake () {
    cake input;
    string name, color;
    double diameter;
    char icing;
    cout << "Name: ";
    cin >> name;
    input.name = name;
    cout << "Color: ";
    cin >> color;
    input.color = color;
    cout << "Diameter: ";
    cin >> diameter;
    input.diameter = diameter;
    cout << "Icing? (y/n) ";
    cin >> icing;
    if (icing == 'y') {
        input.has_icing = true;
    }
    else {
        input.has_icing = false;
    }
    return input;
}

int main() {
    cake input = make_cake ();
    print_cake_info (input);
}

Q4

Write the function change_cake_diameter, which takes a cake and a double as a parameter. change_cake_diameter then multiplies the original diameter by the double and modifies the cake to have this new diameter.

Example cp_9_AC_4q

#include <iostream>
using namespace std;

struct cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void print_cake_info (cake c);
cake make_cake ();

// Write your code for the change_cake_diameter function here.

int main() {
    cake original = { "John", "green", 8.5, true };
    change_cake_diameter (original, 2);
    print_cake_info (original);
}

Q5

Question

Write the edit_cake function, which prompts the user for a new name, color, diameter, and whether or not they want icing. The function modifies the original cake that is passed in as a parameter. Use the make_cake function in your implementation to avoid duplicate code!

Example cp_9_AC_5q

#include <iostream>
using namespace std;

struct cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void print_cake_info (cake c);
cake make_cake ();

// Write your code for the edit_cake function here.

int main() {
    cake original = { "Oops", "orange", 185, true };
    edit_cake (original);
    print_cake_info (original);
}

Answer

Below is one way to implement the program. We call make_cake in edit_cake and then set the original cake equal to the new one.

Example cp_9_AC_5a

#include <iostream>
using namespace std;

struct cake {
    string name;
    string color;
    double diameter;
    bool has_icing;
};

void print_cake_info (cake c);
cake make_cake ();

void edit_cake (cake& c) {
    cake new_cake = make_cake ();
    c = new_cake;
}

int main() {
    cake original = { "Oops", "orange", 185, true };
    edit_cake (original);
    print_cake_info (original);
}

Q6

Write the struct shirt, which has the instance variables color and size.

Example cp_9_AC_6q

#include <iostream>
using namespace std;

// Write your code for the struct shirt here.

int main () {
    shirt t = { "blue", 'L' };
}

Q7

Question

Write the pants structure, which has instance variables size and material.

Example cp_9_AC_7q

#include <iostream>
using namespace std;

// Write your code for the struct pants here.

int main() {
    pants p = { 'S', "denim" };
}

Answer

Below is one way to implement the program. We declare the pants struct and list the instance variables in order.

Example cp_9_AC_7a

#include <iostream>
using namespace std;

struct pants {
    char size;
    string material;
};

int main() {
    pants p = { 'S', "denim" };
}

Q8

Write the struct outfit, which is a nested structure that has a shirt, pants, and has_hat.

Example cp_9_AC_8q

#include <iostream>
using namespace std;

// Write your code for the struct outfit here.

int main () {
    shirt t = { "blue", 'L' };
    pants p = { 'S', "denim" };
    outfit o = { t, p, true };
}

Q9

Question

Write the print_outfit function, which prints out details of the outfit. The output below should be "shirt: blue and L; pants: S and denim; has hat".

Example cp_9_AC_9q

#include <iostream>
using namespace std;

struct shirt {
    string color;
    char size;
};

struct pants {
    char size;
    string material;
};

struct outfit {
    shirt s;
    pants p;
    bool has_hat;
};

// Write your code for the print_outfit function here.

int main() {
    shirt t = { "blue", 'L' };
    pants p = { 'S', "denim" };
    outfit o = { t, p, true };
    print_outfit (o);
}

Answer

Below is one way to implement the program.

Example cp_9_AC_9a

#include <iostream>
using namespace std;

struct shirt {
    string color;
    char size;
};

struct pants {
    char size;
    string material;
};

struct outfit {
    shirt s;
    pants p;
    bool has_hat;
};

void print_outfit (outfit o) {
// "shirt: blue and L; pants: S and denim; has hat"
    cout << "shirt: " << o.s.color << " and " << o.s.size << "; pants:" << o.p.size << " and " << o.p.material << "; ";
    if (o.has_hat) {
        cout << "has hat" << '\n';
    }
    else {
        cout << "does not have hat" << '\n';
    }
}

int main() {
    shirt t = { "blue", 'L' };
    pants p = { 'S', "denim" };
    outfit o = { t, p, true };
    print_outfit (o);
}

Q10

Write the change_shirts and change_pants functions, which both take an outfit as a parameter. change_shirts also takes a shirt as a parameter and change_pants also takes a pants as a parameter. Each function modifies the outfit and changes the shirt or pants to the new input.

If you did Q9, then feel free to copy the print_outfit function from there into this program.

Example cp_9_AC_10q

#include <iostream>
using namespace std;

struct shirt {
    string color;
    char size;
};

struct pants {
    char size;
    string material;
};

struct outfit {
    shirt s;
    pants p;
    bool has_hat;
};

// Write your code for the change_shirts function here.

// Write your code for the change_pants function here.

int main() {
    shirt t = { "blue", 'L' };
    pants p = { 'S', "denim" };
    outfit o = { t, p, true };
    print_outfit (o);
    shirt new_shirt = { "red", 'M' };
    pants new_pants = { 'M', "khakis" };
    change_shirts (o, new_shirt);
    change_pants (o, new_pants);
    print_outfit (o);
}