Question

Please answer using C++

The file lab10movies.cpp contains a program that allows the user to read movie names and movie release dates from a file called movies.txt. The data is read into a single ended linked list. Once all the data has been read in, the user is given a menu option with 3 choices. Choice 1 will list all movies released before a specified year, Choice 2 will list all movies stored in the linked list, and Choice 3 will exit the program. The file lab10movies.cpp is incomplete, the sections you must complete have the tag TODO on them. The main task is to create the function showBeforeYear and have it list all movies before a specified year, if there are no movies before the specified year then let the user know that there are no movies. You can obtain the two files by issuing the following two wget commands wget tars.clarkson.edu/cs141/lab10/movies.txt wget tars.clarkson.edu/cs141/lab10/1ab10movies.cpp

Answer 1

Solution:

lab10movies.cpp

#include<iostream>
#include<string>
#include<fstream>

struct Movie
{
   std::string movieName;
   int yearReleased;
};

//TODO: create a struct called Movie
//TODO: in the struct use a string called movieName to store the movie name
//TODO: in the struct use an int called yearReleased to store the year

//node represents a single node in the linked list
struct node
{
   Movie aMovie;
   node* prevPtr;
};

//Function: menu is used to display an interactive menu to the user
void menu();

//TODO: create a function prototype called showBeforeYear
//TODO: showBeforeYear takes two inputs: a node* and an int
void showBeforeYear(node*,int);

//Function: listMovies is used to display all movies in the linked list
void listMovies(node*);

int main()
{
   std::ifstream inputHandler;       //file handler for input file
   std::string movieNameFromFile;   //store movie name from file
   int movieYearFromFile;           //store movie year from file
   int userInput;                   //get user input for menu interaction
   int userYear;                   //get year from user to list movies
   node* currentPtr = NULL;       //currentPtr points to current list element, initialized to NULL
   node* headPtr = NULL;           //headPtr points to top of list, initialized to NULL

   //Open the movies.text file
   inputHandler.open("movies.txt");
   //Read the first line from the file
   inputHandler >> movieNameFromFile >> movieYearFromFile;

   while (!inputHandler.eof())
   {
       //create a new node called currentPtr
       currentPtr = new node;
  
       //TODO: set the value for currentPtr to the values read from the file
      
       currentPtr->aMovie.movieName=movieNameFromFile;
       currentPtr->aMovie.yearReleased=movieYearFromFile;
      
      
       //set currentPtr->prevPtr to headPtr
       currentPtr->prevPtr = headPtr;

       //update headPtr to currentPtr
       headPtr = currentPtr;

       //read the next line from the file
       inputHandler >> movieNameFromFile >> movieYearFromFile;
   }

   //Close the file
   inputHandler.close();

   //Display the menu to the user
   menu();
   std::cin >> userInput;

   //Validate input
   while (userInput > 3 || userInput < 1)
   {
       //Display the menu to the user
       menu();
       std::cin >> userInput;
   }

   //List movies by year
   if (userInput == 1)
   {
       //TODO: ask the user to enter the year
       //TODO: store the year entered by the user in userYear
       //TODO: call function showBeforeYear with currentPtr and userYear
       std::cout<<"Enter an year:";
       std::cin>>userYear;
       showBeforeYear(currentPtr,userYear);      
       return 0;
   }
   //List all movies
   else if (userInput == 2)
   {
       //Call function listMovies to print all movies
       listMovies(currentPtr);
       return 0;
   }
   //Exit program
   else
   {
       //Show exit message and terminate program
       std::cout << "Exiting program." << std::endl;
       return 0;
   }
}

//Function: menu
//Inputs: none
//Outputs: none
//Errors: none
void menu()
{
   std::cout << "Press 1 to list movies released before a specific year." << std::endl;
   std::cout << "Press 2 to list all movies." << std::endl;
   std::cout << "Press 3 to quit." << std::endl;
   std::cout << "Enter your choice: ";
}

//TODO: create function showBeforeYear
//Function: showBeforeYear
//Inputs: node* currentPtr and int userYear
//Outputs: displays all movies before a specific year
//Errors: none

void showBeforeYear(node* currentPtr, int userYear)
{
   //TODO: function showBeforeYear should list all movies released before userYear
   //TODO: if you find 0 movies before userYear, tell the user that you found no movies

   int movies=0;
   while(currentPtr)
   {
       if(currentPtr->aMovie.yearReleased<userYear)
       {
           movies++;
           std::cout<<currentPtr->aMovie.movieName<<" "<<currentPtr->aMovie.yearReleased<<"\n";
       }
   currentPtr=currentPtr->prevPtr;
   }
   if(movies==0)
       std::cout<<"No movies found";
}

//Function: listMovies
//Inputs: node* currentPtr
//Outputs: displays all movies stored in linked list
//Errors: none
void listMovies(node* currentPtr)
{
   //Loop until currentPtr hits NULL
   while(currentPtr)
   {
       //Print entry from linked list
       std::cout << currentPtr->aMovie.movieName << " released in " << currentPtr->aMovie.yearReleased << std::endl;
       //Move currentPtr to next location
       currentPtr = currentPtr->prevPtr;
   }
}
movies.txt:

Alice_in_Wonderland   2010
Avatar   2009
Avengers:_Age_of_Ultron   2015
Despicable_Me_2   2013
Finding_Dory   2016
Finding_Nemo   2003
Frozen   2013
Furious_7   2015
Iron_Man_3   2013
Jurassic_Park   1993
Jurassic_World   2015
Minions   2015
Shrek_2   2004
Skyfall   2012
Spectre   2015
Spider-Man_3   2007
The_Avengers   2012
The_Dark_Knight   2008
The_Dark_Knight_Rises   2012
The_Jungle_Book   2016
The_Lion_King   1994
The_Secret_Life_of_Pets   2016
Titanic   1997
Toy_Story_3   2010
Zootopia_film   2016

Output:

Activities Terminal Sun 10:25 bhaswanth@jaywanth:-/C++ Files File Edit View Search Terminal Help bhaswanth@jaywanth:~/C+Files$ g++ lab10novies.cpp bhaswanth@jaywanth: /C++ Files ./a.out Press 1 to list movies released before a specific year. Press 2 to list all movies Press 3 to quit. Enter your choice: 1 Enter an year:2005 Titanic 1997 The_Lion_King 1994 Shrek 2 2004 Jurassic Park 1993 Finding_Nemo 2003 bhaswanth@jaywanth:-/C++Files$


Activities Terminal Sun 10:22 bhaswanth@jaywanth:-/C++ Files File Edit View Search Terminal Help bhaswanth@jaywanth:~/C+Filess ./a.out Press 1 to list movies released before a specific year Press 2 to list all movies. Press 3 to quit. Enter your choice: 2 Zootopia_film released in 2016 Toy_Story 3 released in 2010 Titanic released in 1997 The Secret Life of Pets released in 2016 The Lion_King released in 1994 The_Jungle_Book released in 2016 The_Dark_Knight_ Rises released in 2012 The_Dark_Knight released in 2008 The_Avengers released in 2012 Spider-Man_3 released in 2007 Spectre released in 201!5 Skyfall released in 2012 Shrek 2 released in 2004 Minions released in 2015 Jurassic World released in 2015 Jurassic_Park released in 1993 Iron_Man 3 released in 2013 Furious 7 released in 2015 Frozen released in 2013 Finding_Nemo released in 2003 Finding_Dory released in 2016 Despicable_Me_2 released in 2013 Avengers: Age_of_Ultron released in 2015 Avatar released in 2009 Alice in Wonderland released in 2010 bhaswanth@jaywanth:~/C+Filess ./a.out Press 1 to list movies released before a specific year Press 2 to list all movies. Press 3 to quit. Enter your choice: 3 Exiting program bhaswanth@jaywanth: /C++ Files$