A Design for HW2

• My Notes
  • Follow instructions please
  • Why would you do a design?
    • Should it be at the code level?
  • For algorithms
    • There should be sufficient detail so we beleive you can implement this function.
    • But there shouldn't be so much detail it becomes code.
    • This is tough.
    • Use indentation and control structures to show flow (See page 271, or examples below)
  • Plese keep you main very simple.
  • Structure charts are intended to show the relationship between functions in a program.
    • Children of a node are the functions the node calls directly.
    • There are numerous examples in the book, see page 367 for example.
    • They are to help you understand the "Big Picture" of the program and the relationship between the functions.
• My Design
  • Note, your design may differ from mine, that is ok.
  • This is just an idea.
  • Overview
    • This project will classify strings stored in a file as one of the following
      • Perfect Palindrome: The entire phrase is the same forward and backwards.
      • Natural Palindrome: The phrase is the same forward and backwards but there may be additional punctuation or the case of the letters may differ.
      • Palindrome: The letters only are the same forwards and backwards, there may be other non-letter characters, including spaces, in the phrase.
      • Non-palindrome: None of the above.
    • An error will be reported and the program will exit if the an incorrect file name is provided by the user.
  • 
  • Main Routine
    • This routine will characterize a number of strings in a file according to the palindrom classification scheme.

    • OpenInputFile
      Read a line from the file
      while(the input was successful) 
          Type = Classify Palindrome(line) 
          Print Classification
          Read a line from the file
      Close the input file
              

  • OpenInputFile
    • This function will ask the user for a file name and attempt to open it.
    • Input: The input file stream, unopened
    • Output: The input file stream, either opened or in error state.

    • Prompt user for file name
      Attempt to open the file
      If unable to open the file print an error
              

  • Classify Palindrom
    • This function will classify a given string.
    • Note this is a classification only routine, it does not do input or output.
    • Input: A string
    • Output: A string

    • if IsPalindrom(line)
         return that it is a "Perfect Palindrom"
      else
         Strip the punctuation from the line
         Change the line to lower case
         if IsPalindrom(line)
            return that it is a "Natural Palindrom"
         else
            Strip all but alphabetic characters from the line
            if IsPalindrom(line)
               return that it is a "Palindrom"
            else
               return that it is a "Non-palindrome"
      

  • ToLower
    • This routine converts a string to lower case
    • Input: A string
    • Output: A string with all alphabetic characters converted to lower case

    • for each letter in the string
         if the letter is upper case, convert it to lower case.
             

  • StripPunctuation
    • This routine wil remove all punctuation from a string
    • Input A string
    • Output: A string with no punctuation
    • Note: For this function punctuation is defined by ispunct

    • set return value to blank
      for each letter in the string
         if it is not punctuation, add it to the return string
      return the return string.
              

  • AlphaOnlyString
    • This will remove all but alphabetic characters from a string
    • Input: A string
    • Output: A string with everything but alphabetic characters removed.
    • Note: isalpha is used to determine if a character is alphabetic

    • set return value to blank
      for each letter in the string
         if it is an alphabetic character, add it to the return string
      return the return string.
              

  • IsPalindrome
    • This function will determine if a string is a palindrom
    • Input: a string
    • Output: a boolean, true if the string is a palindrome.

    • returnValue = true
      for each letter between position 0 and size/2
         if the letter does not match the letter the same distance from the other end
           returnValue = false;
      return returnValue
            

  • PrintClassification
    • This routine handles all output
    • Input:
      • The line being identified, a string
      • The classification, a string
    • Output: none

    • print quotes
      print the line
      print quotes
      print classification
      print newline