Could you write algorithm and comment for the fllowing C++ code. The form of alg
ID: 3699948 • Letter: C
Question
Could you write algorithm and comment for the fllowing C++ code. The form of algorithm and comment show in the picture. Thank you very much
#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
#include <sstream>
using namespace std;
class Book {
private:
string title;
string author;
public:
string getTitle() {
return title;
}
void setTitle(string title) {
this->title = title;
}
string getAuthor() {
return author;
}
void setAuthor(string author) {
this->author = author;
}
Book(string title, string author) {
this->title = title;
this->author = author;
}
Book() {
title = "NONE";
author = "NONE";
}
};
class User {
private:
string name;
int ratings[100];
int numRatings;
public:
User(string name, int r[], int num) {
this->name = name;
this->numRatings = num;
for (int i = 0; i < num; i++) {
ratings[i] = r[i];
}
}
User() {
name = "NONE";
numRatings = 0;
for (int i = 0; i < 100; i++) {
ratings[i] = 0;
}
}
int getNumRatings() {
return numRatings;
}
void setNumRatings(int numRatings) {
this->numRatings = numRatings;
}
string getName() {
return name;
}
void setName(string name) {
this->name = name;
}
int getRatingAt(int index) {
if (index >= numRatings)
return -1000;
return ratings[index];
}
int setRatingAt(int index, int rating) {
if (index >= numRatings) {
return -1000;
}
if (rating != -5 && rating != -3 && rating != 0
&& rating != 1 && rating != 3 && rating != 5) {
cout << "Invalid Input!" << endl;
return -1;
}
ratings[index] = rating;
cout << "Success!" << endl;
return 0;
}
};
class Library {
private:
Book books[100];
User users[100];
int numOfUsers;
int numOfBooks;
int loginUser;
string toLower(string s) {
for (int i = 0;i < s.length();i++) {
if (s[i] >= 'A'&&s[i] <= 'Z') {
s[i] += 32;
}
}
return s;
}
int findUser(string name) {
for (int i = 0; i < numOfUsers;i++) {
if (users[i].getName() == name) {
return i;
}
}
return -1;
}
int findBook(string name) {
for (int i = 0; i < numOfBooks;i++) {
int len = books[i].getTitle().length();
if (books[i].getTitle().substr(0,len-1) == name) {
return i;
}
}
return -1;
}
int ssd(int i, int j) {
int sum = 0;
for (int k = 0;k < numOfBooks;k++) {
sum += ((users[i].getRatingAt(k) - users[j].getRatingAt(k)) * (users[i].getRatingAt(k) - users[j].getRatingAt(k)));
}
return sum;
}
int mostSimilar() {
int minssd;
int min;
if (loginUser == 0) {
minssd = ssd(loginUser, 1);
min = 1;
}
else {
minssd = ssd(loginUser, 0);
min = 0;
}
for (int i = 0;i < numOfUsers;i++) {
if (i == loginUser)
continue;
if (ssd(loginUser, i) < minssd) {
minssd = ssd(loginUser, i);
min = i;
}
}
return min;
}
public:
Library() :numOfUsers(0), numOfBooks(0) { }
void loadData() {
ifstream bookfile("books.txt");
ifstream userfile("ratings.txt");
if (!bookfile.is_open() || !userfile.is_open()) {
cout << "Launch unsuccessful" << endl;
cout << "Error! books or ratings file could not be found." << endl;
exit(1);
}
string line;
while (!bookfile.eof()) {
if (bookfile.fail()) {
break;
}
getline(bookfile, line);
if (line.empty()) {
continue;
}
line = toLower(line);
int comma = line.find(',');
books[numOfBooks].setAuthor(line.substr(0, comma));
books[numOfBooks].setTitle(line.substr(comma + 1));
numOfBooks++;
}
bookfile.close();
while (!userfile.eof()) {
if (userfile.fail()) {
break;
}
getline(userfile, line);
if (line.empty()) {
continue;
}
line = toLower(line);
int comma = line.find(',');
stringstream ss;
int ratings[100];
ss.str(line.substr(comma + 1));
for (int i = 0; i < numOfBooks;i++) {
int rating;
ss >> rating;
ratings[i] = rating;
}
users[numOfUsers++] = User(line.substr(0, comma), ratings, numOfBooks);
}
userfile.close();
cout << "Data Loaded successfully!" << endl;
}
void login() {
cout << "Welcome to the Library, What is your name?:" << endl;
string name;
getline(cin, name);
while (name.empty()) {
cout << "You provided an empty user name, Please provide a valid user name to login or register:" << endl;
cout << "Enter your name again:" << endl;
getline(cin, name);
}
string lowername = toLower(name);
int res = findUser(lowername);
if (res != -1) {
cout << "Welcome back, " << name << endl;
loginUser = res;
}
else {
cout << "Welcome to the Library, " << name << endl;
User newUser;
newUser.setName(toLower(name));
newUser.setNumRatings(numOfBooks);
loginUser = numOfUsers;
users[numOfUsers] = newUser;
numOfUsers++;
}
}
char menu() {
string input;
while (true) {
cout << "Would you like to (v)iew your ratings, (r)ate a book, (g)et recommendations, or (q)uit?:" << endl;
getline(cin, input);
if (input.length() == 1
&& (input[0] == 'v' || input[0] == 'V'
|| input[0] == 'r' || input[0] == 'R'
|| input[0] == 'g' || input[0] == 'G'
|| input[0] == 'q' || input[0] == 'Q')) {
return input[0];
}
else {
cout << "Please input a valid choice" << endl;
}
}
}
void viewRatings() {
bool hasRated = false;
for (int i = 0; i < numOfBooks;i++) {
if (users[loginUser].getRatingAt(i) != 0) {
hasRated = true;
break;
}
}
if (!hasRated) {
cout << "You have not rated any books as yet: " << endl;
return;
}
cout << "Here are the books that you have rated: " << endl;
for (int i = 0;i < numOfBooks;i++) {
if (users[loginUser].getRatingAt(i) != 0) {
string s1 = books[i].getTitle();
int ans = users[loginUser].getRatingAt(i);
int len = s1.length();
s1 = s1.substr(0,len-1);
cout << "Title : " << s1 << endl;
cout << "Rating : " << ans << endl;
cout << "------------------------------" << endl;
}
}
}
void rateBook() {
while (true) {
cout << "Enter the name of the book that you would like to rate:" << endl;
string title;
string str;
getline(cin, title);
str = title;
string lowerTitle = toLower(title);
cout << "Enter your rating of the book:" << endl;
int rating;
cin >> rating;
getchar();
int index = findBook(lowerTitle);
if (index == -1) {
cout << "The book you requested does not exist in the database" << endl;
}
else {
users[loginUser].setRatingAt(index, rating);
cout<<"Thank-you. The rating for the book titled "<<str<<" has been updated to "<<rating<<endl;
return;
}
}
}
void recommend() {
int similar = mostSimilar();
bool hasRecommend = false;
for (int i = 0; i < numOfBooks;i++) {
if (users[similar].getRatingAt(i) >= 3 && users[loginUser].getRatingAt(i) == 0) {
hasRecommend = true;
break;
}
}
if (!hasRecommend) {
cout << "There are no recommendations for you at present" << endl;
return;
}
cout << "Here are some of the books that we think you would like" << endl;
int recommendBooks = 0;
for (int i = 0; i < numOfBooks && recommendBooks < 10;i++) {
if (users[similar].getRatingAt(i) >= 3 && users[loginUser].getRatingAt(i) == 0) {
int l1 = books[i].getTitle().length();
int l2 = books[i].getAuthor().length();
cout << books[i].getTitle().substr(0,l1-1) << " by " << books[i].getAuthor()<< endl;
recommendBooks++;
}
}
}
void quit() {
ofstream out("ratings_new.txt");
for (int i = 0;i < numOfUsers;i++) {
out << users[i].getName() << ",";
for (int j = 0;j < numOfBooks;j++) {
out << users[i].getRatingAt(j) << " ";
}
out << endl;
}
out.close();
cout << "Data successfully saved. Goodbye!" << endl;
}
};
int main()
{
Library library;
library.loadData();
library.login();
char opt;
while (true) {
opt = library.menu();
switch (opt) {
case 'v':
case 'V':
library.viewRatings();
break;
case 'r':
case 'R':
library.rateBook();
break;
case 'g':
case 'G':
library.recommend();
break;
case 'q':
case 'Q':
library.quit();
return 0;
}
}
7 using namespace std; ALgorithe: that checks what range a given NPG folls into . 1. Take the mpg value passed to the function. 11 12 13 14 15 16 Comments (10 points) 2 Check f tt is greater than se If yes, then print "Nice Job . If not, then check f t ts greater than 25 Alorithm If yes, then print "Not great, but oay 4. If not, then print "So bad, so very, very bad (10 points) Input parometers: iles per gollon (Float type 18Output:dfferent string bosed on three cotegortes of G:50, 25-49, and Less than 25 Returns: nothing 21 23 void checkPG(Float mpg) 50) check f the Input volue ts greater than 5e 25 26 27 28 29 30 31 32 cout ee "Nice job e endl; 7 output message lse if(ng25) 7/ff not, check f is greater than 25 coutExplanation / Answer
Hi Student,
Please find the comments and algos.
//include the headers
#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
#include <sstream>
//namespace
using namespace std;
/*
* Class Book has two data members
* a. title - keeps the title of the book
* b. author - keeps the author of the book
*
*/
class Book {
private:
string title; // data member title
string author; // data member author
public:
/* getter for private data member title */
string getTitle() {
return title;
}
/* setter for private data member title */
void setTitle(string title) {
this->title = title;
}
/* getter for private data member author */
string getAuthor() {
return author;
}
/* setter for private data member author */
void setAuthor(string author) {
this->author = author;
}
/* constructor with title and author */
Book(string title, string author) {
this->title = title;
this->author = author;
}
/* default constructor */
Book() {
title = "NONE";
author = "NONE";
}
};
/*
* Class User
*
*
*
*/
class User {
private:
string name;
int ratings[100];
int numRatings;
public:
/* constructor to set name and ratings and number ratings */
User(string name, int r[], int num) {
this->name = name;
this->numRatings = num;
for (int i = 0; i < num; i++) {
ratings[i] = r[i];
}
}
/* default constructor */
User() {
name = "NONE";
numRatings = 0;
/* initialize the ratings with initial value of 0 */
for (int i = 0; i < 100; i++) {
ratings[i] = 0;
}
}
/* getter for private data member numRatings */
int getNumRatings() {
return numRatings;
}
/* setter for private data member numRatings */
void setNumRatings(int numRatings) {
this->numRatings = numRatings;
}
/* getter for private data member name */
string getName() {
return name;
}
/* setter for private data member name */
void setName(string name) {
this->name = name;
}
/*
* Algorithm to get the ratings at a particular index
* 1. If index is greater than the total ratings
* returns -1000
* Else
* returns the rating at corresponding index
*/
int getRatingAt(int index) {
if (index >= numRatings) // condition check if index provided is greater than the total ratings
return -1000;
return ratings[index];
}
/*
* Algorithm to set the ratings at a particular index
* 1. If index is greater than the total ratings
* returns -1
* 2.If index is any of -5,-3,0,3,5
* Sucessfully sets the rating to the index
* Prints Success message to console
* returns 0
* Else
* returns -1 for other ratings
*/
int setRatingAt(int index, int rating) {
if (index >= numRatings) {
return -1000;
}
if (rating != -5 && rating != -3 && rating != 0
&& rating != 1 && rating != 3 && rating != 5) {
cout << "Invalid Input!" << endl;
return -1;
}
ratings[index] = rating;
cout << "Success!" << endl;
return 0;
}
};
class Library {
private:
Book books[100]; // data member to store books - max 100
User users[100]; // data member to store users - max 100
int numOfUsers; // data member to keep count of num of users
int numOfBooks; // data members to keep count of num of books
int loginUser; // data member to keep login status
/*Algorithm toLower()
* Input : Takes a string
* Output : Returns the string after converting to lower case
*
*/
string toLower(string s) {
for (int i = 0;i < s.length();i++) {
if (s[i] >= 'A'&&s[i] <= 'Z') {
s[i] += 32;
}
}
return s;
}
/* Algorthm findUser()
* 1. Takes a name as input
* 2. Check is its already an user
* If Yes returns the position
* Else
* reurns -1
*
* Input : String name
* Output : Returns the user num or -1 if not found
*
*/
int findUser(string name) {
for (int i = 0; i < numOfUsers;i++) {
if (users[i].getName() == name) {
return i;
}
}
return -1;
}
/* Algorthm findBook
* 1. Takes a name of book as input
* 2. Check is its already present
* If Yes returns the position
* Else
* reurns -1
*
* Input : String name
* Output : Returns the user num or -1 if not found
*
*/
int findBook(string name) {
for (int i = 0; i < numOfBooks;i++) {
int len = books[i].getTitle().length(); // take the length of the title
if (books[i].getTitle().substr(0,len-1) == name) { // check if book is present
return i;
}
}
return -1;
}
int ssd(int i, int j) {
int sum = 0;
for (int k = 0;k < numOfBooks;k++) {
sum += ((users[i].getRatingAt(k) - users[j].getRatingAt(k)) * (users[i].getRatingAt(k) - users[j].getRatingAt(k)));
}
return sum;
}
int mostSimilar() {
int minssd;
int min;
if (loginUser == 0) {
minssd = ssd(loginUser, 1);
min = 1;
}
else {
minssd = ssd(loginUser, 0);
min = 0;
}
for (int i = 0;i < numOfUsers;i++) {
if (i == loginUser)
continue;
if (ssd(loginUser, i) < minssd) {
minssd = ssd(loginUser, i);
min = i;
}
}
return min;
}
public:
Library() :numOfUsers(0), numOfBooks(0) { }
/* ALgorithm loadData()
* Loads the books from books.txt
* Loads the ratings for books from ratings.txt
*
* Input : void
* Return : coid
*/
void loadData() {
ifstream bookfile("books.txt");
ifstream userfile("ratings.txt");
if (!bookfile.is_open() || !userfile.is_open()) {
cout << "Launch unsuccessful" << endl;
cout << "Error! books or ratings file could not be found." << endl;
exit(1);
}
string line;
while (!bookfile.eof()) {
if (bookfile.fail()) {
break;
}
getline(bookfile, line);
if (line.empty()) {
continue;
}
line = toLower(line);
int comma = line.find(',');
books[numOfBooks].setAuthor(line.substr(0, comma));
books[numOfBooks].setTitle(line.substr(comma + 1));
numOfBooks++;
}
bookfile.close();
while (!userfile.eof()) {
if (userfile.fail()) {
break;
}
getline(userfile, line);
if (line.empty()) {
continue;
}
line = toLower(line);
int comma = line.find(',');
stringstream ss;
int ratings[100];
ss.str(line.substr(comma + 1));
for (int i = 0; i < numOfBooks;i++) {
int rating;
ss >> rating;
ratings[i] = rating;
}
users[numOfUsers++] = User(line.substr(0, comma), ratings, numOfBooks);
}
userfile.close();
cout << "Data Loaded successfully!" << endl;
}
/* Algorithm login
* Takes username
* If exising user then print a welcome messge
* Else register the user and print a welcome message
*
* Input : void
* Outptut : void
*/
void login() {
cout << "Welcome to the Library, What is your name?:" << endl;
string name;
getline(cin, name);
while (name.empty()) {
cout << "You provided an empty user name, Please provide a valid user name to login or register:" << endl;
cout << "Enter your name again:" << endl;
getline(cin, name);
}
string lowername = toLower(name);
int res = findUser(lowername);
if (res != -1) {
cout << "Welcome back, " << name << endl;
loginUser = res;
}
else {
cout << "Welcome to the Library, " << name << endl;
User newUser;
newUser.setName(toLower(name));
newUser.setNumRatings(numOfBooks);
loginUser = numOfUsers;
users[numOfUsers] = newUser;
numOfUsers++;
}
}
char menu() {
string input;
while (true) {
cout << "Would you like to (v)iew your ratings, (r)ate a book, (g)et recommendations, or (q)uit?:" << endl;
getline(cin, input);
if (input.length() == 1
&& (input[0] == 'v' || input[0] == 'V'
|| input[0] == 'r' || input[0] == 'R'
|| input[0] == 'g' || input[0] == 'G'
|| input[0] == 'q' || input[0] == 'Q')) {
return input[0];
}
else {
cout << "Please input a valid choice" << endl;
}
}
}
void viewRatings() {
bool hasRated = false;
for (int i = 0; i < numOfBooks;i++) {
if (users[loginUser].getRatingAt(i) != 0) {
hasRated = true;
break;
}
}
if (!hasRated) {
cout << "You have not rated any books as yet: " << endl;
return;
}
cout << "Here are the books that you have rated: " << endl;
for (int i = 0;i < numOfBooks;i++) {
if (users[loginUser].getRatingAt(i) != 0) {
string s1 = books[i].getTitle();
int ans = users[loginUser].getRatingAt(i);
int len = s1.length();
s1 = s1.substr(0,len-1);
cout << "Title : " << s1 << endl;
cout << "Rating : " << ans << endl;
cout << "------------------------------" << endl;
}
}
}
void rateBook() {
while (true) {
cout << "Enter the name of the book that you would like to rate:" << endl;
string title;
string str;
getline(cin, title);
str = title;
string lowerTitle = toLower(title);
cout << "Enter your rating of the book:" << endl;
int rating;
cin >> rating;
getchar();
int index = findBook(lowerTitle);
if (index == -1) {
cout << "The book you requested does not exist in the database" << endl;
}
else {
users[loginUser].setRatingAt(index, rating);
cout<<"Thank-you. The rating for the book titled "<<str<<" has been updated to "<<rating<<endl;
return;
}
}
}
/* Algorithm recommend
*
*
*
*/
void recommend() {
int similar = mostSimilar();
bool hasRecommend = false;
for (int i = 0; i < numOfBooks;i++) {
if (users[similar].getRatingAt(i) >= 3 && users[loginUser].getRatingAt(i) == 0) {
hasRecommend = true;
break;
}
}
if (!hasRecommend) {
cout << "There are no recommendations for you at present" << endl;
return;
}
cout << "Here are some of the books that we think you would like" << endl;
int recommendBooks = 0;
for (int i = 0; i < numOfBooks && recommendBooks < 10;i++) {
if (users[similar].getRatingAt(i) >= 3 && users[loginUser].getRatingAt(i) == 0) {
int l1 = books[i].getTitle().length();
int l2 = books[i].getAuthor().length();
cout << books[i].getTitle().substr(0,l1-1) << " by " << books[i].getAuthor()<< endl;
recommendBooks++;
}
}
}
/*Algorithm Quit
* 1. Creates an ofstream to save the data
* 2. For all the users
* Print the name and ratings for all books
* 3. Save the data
* 4. Close the file
*
*/
void quit() {
ofstream out("ratings_new.txt");
for (int i = 0;i < numOfUsers;i++) {
out << users[i].getName() << ",";
for (int j = 0;j < numOfBooks;j++) {
out << users[i].getRatingAt(j) << " ";
}
out << endl;
}
out.close();
cout << "Data successfully saved. Goodbye!" << endl;
}
};
int main()
{
Library library; //initialize the library object
library.loadData(); // call data member
library.login(); // check for login
char opt;
while (true) {
opt = library.menu(); // display the menu
switch (opt) { //
case 'v':
case 'V':
library.viewRatings(); // show ratings
break;
case 'r':
case 'R':
library.rateBook(); // rate Book
break;
case 'g':
case 'G':
library.recommend(); // show recommendation
break;
case 'q':
case 'Q':
library.quit(); // quit the program
return 0;
}
}
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