Question

Hey Guys ,

I need help with this assignment:

This component of the final exam will have two data structures. The two data structures will be a stack and the other will be a hashmap. The hashmap object will be added to the stack every time the user picks an answer. The hashmap will have a key and value. The key will be the timestamp (system time when the user selected a choice) and the value will be the choice the user picked. For example, if the question was Buffalo vs. Pittsburgh and the user picked Buffalo at 10pm, then the timestamp (key) will be 10pm and the value would be Buffalo. This hashmap object will then be added to the stack. You will have a hashmap object for every answer to the questions.

Here what I did for java:

import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Scanner;
import java.util.Stack;


class userNewChoices{
        private Scanner scan = new Scanner(System.in);
        private Stack<Map> answers = new Stack<Map>();


        
        
        public void close() {
                scan.close();
        }


        public String getChoices(String choice1, String choice2) {
                System.out.println();
                System.out.println("Please choose from the following options: ");
                System.out.println("#1" + choice1);
                System.out.println("#2" + choice2);
                System.out.println("Enter your choice here: ");


                String userChoice = scan.next();
                return userChoice;
        }
        public void userStack(String userChoice) {
                Map<String,String> map1=new HashMap<>();
                String timeStamp = new SimpleDateFormat("ss.mm.HH.dd.MM.yyyy").format(new Date());


                map1.put(timeStamp, userChoice);
                answers.push(map1);
        }
        public void printAnswerStack(){
                Iterator userChoiceMap = answers.iterator();
                System.out.println();
                System.out.println("User stacks are as fellowed ");
                System.out.println();
                while(userChoiceMap.hasNext()) {
                        System.out.println(userChoiceMap.next());
                }
        }
}


public class sportGames {
        public static void main(String args[])
        {
                
        }
}

I dont know where to go from here.

Answer 1

Note:

- The code has been developed and tested on following platform:

1. Java openjdk version "1.8.0_242".

2. Linux Ubuntu OS.

- Feel free to add your queries in the comment section (if any).

Explanation:

- For demo purpose, I've asked user to enter choice (out of Buffalo/Pittsburgh) 5 times. You can choose your own implementation over it.

- For validation, I've created printUserAnswersStack() method that'll display hashmap contents inserted in stack.

Source code:

import java.text.SimpleDateFormat;
import java.util.Collections;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.HashMap;
import java.util.Scanner;
import java.util.Stack;

class UserChoiceRecord{
   private Scanner scan = new Scanner(System.in);
   private Stack<Map> userAnswers = new Stack<Map>();

   // close Scanner object to avoid resource leak
   public void close(){
       scan.close();
   }

   // get user choice out of given 2 options
   public String getUserChoice(String choice1, String choice2){
       System.out.println();
       System.out.println("You have following options:");
       System.out.println("#1 " + choice1);
       System.out.println("#2 " + choice2);
       System.out.println("Enter your choice:");

       String userChoice = scan.next();

       return userChoice;
   }

   // create stack for the choices entered by user
   public void createUserChoiceStack(String userChoice){
       // record current timestamp. The timestamp will be in format yyyy.MM.dd.HH.mm.ss
       String timeStamp = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss").format(new Date());
       Map<String, String> userAnswer = new HashMap<String, String>();
      
       // create a key-value pair in hashmap
       userAnswer.put(timeStamp, userChoice);
      
       // push the hashmap contents into stack
       userAnswers.push(userAnswer);
   }

   // display the user choices from the stack
   public void printUserAnswersStack(){
       Iterator userChoicesMap = userAnswers.iterator();

       System.out.println();
       System.out.println("The user choices as in stack are as follows:");
       System.out.println();

       while(userChoicesMap.hasNext()){
           System.out.println(userChoicesMap.next());
       }
   }

   public static void main(String ...arg){
       UserChoiceRecord record = new UserChoiceRecord();
      
       // ask for user choice 5 times, create a singleton map from them and push that map into stack
       for(int i = 0; i < 5; ++i){
           record.createUserChoiceStack(record.getUserChoice("Buffalo", "Pittsburgh"));
       }
      
       // display the values pushed into the stack
       record.printUserAnswersStack();

       record.close();
   }
}

Attached are the code screenshots for your reference.

Sample output: