Prelim 2025 code

• What type of list is used to store allowed numbers?

  List<int>
• What is the maximum number of targets allowed in the game?

  20
• What does the user input "y" signify in the program?

  To play the training game
• What are the maximum values for MaxNumber and MaxTarget in the training game?

  Both are 1000
• What is the initial list of targets in the training game?

  { -1, -1, -1, -1, -1, 23, 9, 140, 82, 121, 34, 45, 68, 75, 34, 23, 119, 43, 23, 119 }
• What happens if the user input is valid?

  It converts to RPN and checks numbers
• How does the program determine if the user input evaluation is a target?

  By checking against the Targets list
• What does the method RemoveNumbersUsed do?

  Removes numbers used from NumbersAllowed
• What is the purpose of the UpdateTargets method?


  To shift targets and add a new one
• What does the CheckValidNumber method validate?

  If a number is within the valid range
• What does the DisplayState method show?

  Current targets, allowed numbers, and score
• What is the format of the user input expected by CheckIfUserInputValid?

  Regular expression for valid expressions
• What does the GetTarget method do?

  Generates a random target number
• How many targets are initialized to -1 in CreateTargets?

  5
• What does the FillNumbers method do in the training game?

  Returns a fixed list of numbers
• What are the main components of the PlayGame method?

  • Displays current state
  • Accepts user input
  • Validates input
  • Evaluates input against targets
  • Updates score and targets
• What are the steps involved in converting user input to RPN?

  1. Initialize position and precedence
  2. Extract operands and operators
  3. Apply operator precedence rules
  4. Build RPN expression
• What are the rules for evaluating RPN expressions?

  • Use a stack to hold operands
  • Apply operators to the top two operands
  • Push the result back onto the stack
  • Return -1 for non-integer results
• What are the key features of the CheckNumbersUsedAreAllInNumbersAllowed method?

  • Checks if all used numbers are allowed
  • Compares user input with allowed numbers
  • Returns true if all are valid
• What is the significance of the Score variable in the game?

  • Tracks the player's score
  • Increases when a target is hit
  • Decreases for invalid inputs
• What is the role of the EvaluateRPN method?

  • Evaluates the RPN expression
  • Returns the result or -1 for errors
  • Uses a stack for calculations
• What are the conditions for game over in the PlayGame method?

  • All targets are hit
  • User input is invalid
  • Score reaches a certain limit
• What is the purpose of the DisplayTargets method?

  • Shows current targets in the game
  • Indicates which targets are hit
  • Formats output for clarity
• What does the GetNumberFromUserInput method do?

  • Extracts numbers from user input
  • Advances position in the input string
  • Returns -1 if no number is found
• What is the purpose of the Regex class in the program?

  • Validates user input format
  • Matches patterns in strings
  • Ensures correct number formats
• What is the significance of the Random class in the program?

  • Generates random numbers for targets
  • Ensures unpredictability in the game
  • Used for both allowed numbers and targets
• What are the main types of games available in the program?

  • Training game
  • Random game
• What is the role of the Console class in the program?

  • Handles user input and output
  • Displays game state and score
  • Reads user commands
• What are the key components of the program's structure?

  • Main method
  • Game logic methods
  • Input validation methods
  • Display methods
• What is the significance of the internal class in the program?

  • Encapsulates program logic
  • Restricts access to the class
  • Organizes code for clarity
• What is the purpose of the List class in the program?

  • Stores dynamic collections of data
  • Allows easy manipulation of elements
  • Used for targets and allowed numbers
• What is the significance of the static keyword in the program?

  • Indicates class-level methods and variables
  • Allows access without creating an instance
  • Used for utility functions
• What is the purpose of the namespace in the program?

  • Organizes code into logical groups
  • Prevents naming conflicts
  • Enhances code readability
• What is the role of the Dictionary class in the program?

  • Stores key-value pairs for operator precedence
  • Allows fast lookups of operator priorities
  • Used in RPN conversion logic
• What is the significance of the Console.WriteLine method?

  • Outputs text to the console
  • Displays game information and prompts
  • Used for user interaction
• What is the purpose of the List<int> type in the program?

  • Stores integers for targets and allowed numbers
  • Provides dynamic resizing capabilities
  • Facilitates easy data manipulation
• What is the significance of the Main method in the program?

  • Entry point for the application
  • Initializes game variables and starts the game
  • Controls the flow of the program
• What is the purpose of the Skeleton Program code?

  To facilitate the AQA A Level Paper 1 exam
• What programming environment is used for the code?

  Visual Studio Community Edition
• What is the maximum number of targets allowed in the game?

  20