.. _homework4:

Homework 4 (Due 6 pm, Monday, 11/06/2017)
##########################################################################

Please submit your homework to your git repo by
**6 pm, Monday, 11/06/2017**.


1. Python provides a built-in function called ``len`` that returns the
   length of a string, so the value of ``len('dongwook')`` is 8.
   Write a function named ``right_justify`` that takes a string named
   ``s`` as a parameter and prints the string with enough leading
   spaces so that the last letter of the string is in column 70 of the
   display::

     >>> right_justify('yourFirstName')
                                                                      yourFirstName
								                  ^
								                 # 70th column
										   
2. Consider the following function example ``do_twice`` that takes
   a function object as an argument and calls it twice::

     def do_twice(f):
           f()
	   f()

   Here is an example that uses ``do_twice`` to call a function named
   ``print_spam`` twice::

     def print_spam():
           print 'spam'

     do_twice(print_spam)

   
   (a) Type this example into a script and test it.
   (b) Modify ``do_twice`` so that it takes two arguments, a function
       object and a value, and calls the function twice, passing the
       value as an argument.
   (c) Write a more general version of ``print_spam``, called
       ``print_twice``, that takes a string as a parameter and prints
       it twice.
   (d) Use the modified version of ``do_twice`` to call
       ``print_twice`` twice, passing `spam` as an argument.

3. Write a function called ``is_sorted`` that takes a list as a
   parameter and returns ``True`` if the list is sorted in ascending
   order and ``False`` otherwise. You can assume that the elements of
   the list can be compared with the relational operators ``<``,
   ``>``, etc. For example, ``is_sorted([1,2,2])`` should return
   ``True`` and ``is_sorted(['b','a'])`` should return ``False``.

4. Write a function that takes a list of numbers and returns the
   cumulative sum; that is, a new list where the *i* th element is the
   sum of the first *i+1* elements from the original list. For
   example, the cumulative sum of ``[1,2,3]`` is ``[1,3,6]``.

5. Write a function ``print_yourName`` that takes first and last names as a list (e.g.,
   ``['dongwook', 'lee']``) and capitalizes the first characters of
   the first and last names::

     >>> print_yourName(['dongwook','lee'])
     Dongwook Lee

   Implement the function so that if a
   second argument ``False`` is passed in as an extra argument,
   then it prints out the full name as `Lee, Dongwook` (there is a
   space between ``,`` and ``Dongwook``)::

     >>> print_yourName(['dongwook','lee'], False)
     Lee, Dongwook

   The  default option for the second argument is
   either without it, or with ``True``,
   both of which should print out the
   full name as ``Dongwook Lee``::
     
     >>> print_yourName(['dongwook','lee'])
      Dongwook Lee

     >>> print_yourName(['dongwook','lee'], True)
     Dongwook Lee

6. A word is called a palindrome if it is spelled the same backward
   and forward. Examples are *noon*, *madam*, *redivider*, *bob*, or
   *racecar*. Recursively, a word is a palindrome if the first and
   the last letters are the same and the middle part is a palindrome.
   Write a python routine that takes a string argument (i.e., words)
   and returns ``True`` if it is a palindrome and ``False``
   otherwise. 

7. Write a Python routine that takes three real numbers and check if
   they can form a triangle. Your routine returns ``True`` if they
   form a triangle and ``False`` otherwise.
   
     
8. Let's now start learning LaTeX. This time, I am only asking you to
   read through the instructor's online lecture note on LaTex, as
   offered as a part of AMS 200 this quarter. Please make sure you
   install a proper LaTeX distribution on your machine. Later, you're
   going to write some homework reports and a final project report
   using LaTeX, so it is a good time to learn it. The link is found at:
   
    * `AMS 200 on LaTeX <https://users.soe.ucsc.edu/~dongwook/wp-content/uploads/2017/ams200/_build/html/index.html>`_

9. Let's make your Sphinx webpage look more interesting. One way to
   start with is to post your homework solutions of problems 1 to 7 to your webpage. 
   Please make sure you post them *24 hours after*  the deadline,
   i.e., you can start posting your solutions
   *after* 6 pm, Tuesday, 11/7/17 and *before* 6 pm, Wednesday,
   11/8/17. It is recommended that you post your codes in an organized way.