• (1) IDLE (simplest to set up and to learn, but does not have as many features as the other choices, but it is sufficient for CSE 415);
• (2) PyCharm (a commercially-developed, state-of-the-art Python development environment).
• (3) a Conda-managed installation of command-line Python, under Linux, Darwin, or Cygwin (advanced Python developers do this especially if they need to support alternative Python versions and package installations);

The file a1_exercises.py is a starting template. Edit this file to develop your solutions for Part 1. The file test_functions.py contains a few simple tests that will help you in debugging your solutions. To run the tests, in bash or other Linux environment, type:

python -m unittest test_functions.py

def is_quintuple(n):
    """Return True if n is a multiple of 5; False otherwise."""
    pass

def last_prime(m):
    """Return the largest prime number p that is less than or equal to m.
    You might wish to define a helper function for this.
    You may assume m is a positive integer."""
    pass

def quadratic_roots(a, b, c):
    """Return the roots of a quadratic equation (real cases only).
    Return results in tuple-of-floats form, e.g., (-7.0, 3.0)
    Return the string "complex" if real roots do not exist."""
    pass

def new_quadratic_function(a, b, c):
    """Create and return a new, anonymous function (for example
    using a lambda expression) that takes one argument x and 
    returns the value of ax^2 + bx + c."""
    pass

def perfect_shuffle(even_list):
    """Assume even_list is a list of an even number of elements.
    Return a new list that is the perfect-shuffle of the input.
    For example, [0, 1, 2, 3, 4, 5, 6, 7] => [0, 4, 1, 5, 2, 6, 3, 7]"""
    pass

def list_of_5_times_elts_plus_1(input_list):
    """Assume a list of numbers is input. Using a list comprehension,
    return a new list in which each input element has been multiplied
    by 5 and then has 1 added to it."""
    pass

def double_vowels(text):
    """Return a new version of text, with all the vowels doubled.
    For example:  "The *BIG BAD* wolf!" => "Thee *BIIG BAAD* woolf!".
    For this exercise assume the vowels are 
    the characters A,E,I,O, and U (and a,e,i,o, and u).
    Maintain the case of the characters."""
    pass

def count_words(text):
    """Return a dictionary having the words in the text as keys,
    and the numbers of occurrences of the words as values.
    Assume a word is a substring of letters and digits and the characters
    '-', '+', *', '/', '@', '#', '%', and "'" separated by whitespace,
    newlines, and/or punctuation (characters like . , ; ! ? & ( ) [ ] { } | : ).
    Convert all the letters to lower-case before the counting."""
    pass

In this part of the assignment, you'll write methods for classes that deal with state-space search. These methods are not implementations of search algorithms; those will come in the second assignment. Rather, they deal with the basic infrastructure needed for problem formulation.

In problem solving, a state is a data object that represents the components of a possible solution or partial construction in attempting to find a solution, in one particular configuration. For example, in Tic-Tac-Toe, a state is a representation of the board at one particular point in a game. At the beginning of the game, there is the initial state which represents the empty 3-by-3 grid. Each time a move is made in the game, one state is used to construct another. Consider the following class definition for states of Tic-Tac-Toe.

Define the following methods for this class.

    def __str__(self):
        '''Return a string representation of the
           state that show the Tic-Tac-Toe board as a 2-D ASCII display.'''
        pass      

    def __deepcopy__(self):
        '''Return a new instance with the same board arrangement 
           and player to move.'''
        pass      

    def __eq__(self, other):
        '''Return True iff two states are equal.'''
        pass      
    

Consider the following class definition for operators of Tic-Tac-Toe.

class TTT_Operator:
    def __init__(self, who, row, col):
        self.who = who
        self.row = row
        self.col = col
    

Define the following methods for this class of operators.

    def is_applicable(self, state):
        '''Return True iff it would be legal to apply
           this operator to the given state.'''
        pass

    def apply(self, state):
        '''Return a new state object that represents the
           result of applying this operator to the given state.'''
        pass
    

1. Q. Will we be graded on style?
   A. See the above.
2. Q. When I submit my code, will additional test cases be run on my functions, other than those distributed with the starter code?
   A. In general, yes. Also, you are encouraged to develop test cases of your own, to help you debug your code's behavior on possible edge cases.