Assignment 2

1. Demo problem. Consider a number like 14. We're going to iteratively divide by 2 using integer division as follows:

   14 // 2 = 7
   7 // 2 = 3
   3 // 2 = 1
     

   Here, it took three successive "divides" by 2 for 14 to reach 1.

   In your assignment2.pdf, work through how many divides it takes for 1000.

   For the programming part, we will prompt the user for an integer and count the number of divides. In fact, we will keep prompting the user for integers, computing and reporting the number of divides for each, until the user decides "enough". When the user types a negative number to indicate "enough" we stop prompting. Here is sample output:

   Enter an integer: 14
   Number of divides for n=14: 3
   Enter an integer: 64
   Number of divides for n=64: 6
   Enter an integer: 33
   Number of divides for n=33: 5
   Enter an integer: -1
   Thank you!
     

   Here, the user first entered 14 (resulting in 3 divides), then entered 64 (resulting in 6 divides), then 33 (resulting in 5 divides), -1 to stop.

   There are two while-loops at work, one in iterating over user input, and the other in iterative divides.

   At this point, do not read further and try to write down pseudocode to solve the problem.

   Now examine the solution

   Don't forget to submit your solutions to the exercises within.

2. Let's use a while-loop to perform the most basic type of compound-interest calculation. Suppose you start with $1,000 as your principal and that each year you accumulate 10% in interest. Then, after the first year, you would have $1,100 (since 100 is 10% of 1000). The next year you would add 10% of $1,100 to $1,100. What we'd like to know is: how many years does it take for this compounding process to reach a desired target of $10,000?

   Write code below to perform this calculation:

   def compute_num_years(annual_rate, principal, target):
       # Write your code here
   
   n = compute_num_years(10, 1000, 10000)
   print('num years =', n)                  # Should print 25
   
   n = compute_num_years(8, 1000, 10000)
   print('num years =', n)                  # Should print 30
     

   Write your code in my_compound_interest.py.

3. We've used wordtool before to loop through nouns and verbs. For example, let's print the first 10 nouns:

   words = wordtool.get_nouns()
   for i in range(10):
       print(words[i])
     

   Consider the following:

   def has_all_vowels(w):
       # Write code here to determine whether w has all 5 vowels
   
   words = wordtool.get_nouns()
   
   position = 0
   
   # Write a while-loop here to stop at the first noun that 
   # has all 5 vowels
   
   print('Found', words[position], 'at position', position)
   # Should print: 
   # Found argumentation at position 456
     

   Thus, in my_has_all_vowels.py your goal here is to write code for the function has_all_vowels() so that it returns True or False, and then write a while loop that tries nouns in sequence until you find the first noun that has all vowels. In your assignment2.pdf, report on the first verb that has all vowels. You will need wordtool.py and wordsWithPOS.txt.

4. This next problem is about processing data from text files. To start, download drawtool.py and my_rectangles.py, and then read through the latter. Then download these three files: rectangles1.txt, rectangles2.txt, rectangles3.txt as well. Examine the data files to see that each line except the first has data about a single rectangle: the x,y coordinates of the bottom left corner, and the width and height. For example, the first file is:

   2
   1 1 2 3
   5 5 3 2
     

   This indicates 2 rectangles. The first rectangle has its bottom left corner at (1,1), has width 2 and height 3.

   Now run the my_rectangles.py program. Then, in the program, change rectangles1.txt to rectangles2.txt. And once again to rectangles3.txt. You can then look at the files and confirm that you are indeed seeing the rectangles in those files. You should also see some rectangles overlap (intersect) with others, while some rectangles are entirely isolated.

   Now for the assignment. Your goal is to identify which rectangles intersect another, and to draw them in red. You'll see that all you have to write is the code that determines the intersections.

   Note: use while-loops instead of for-loops in your part of the code.

   When you use the rectangles1.txt, you should see:

   

   With rectangles2.txt, you should see:

   

   With rectangles3.txt:

   

5. By now you've heard the term programmer, possibly even software developer. Identify at least 5 more such job titles that relate to computer programming. Then, in your assignment2.pdf, write 1-2 sentences for each, so that they are all distinguished from other each other.

A2.6 Audio:

How to submit:

• Write all your programs and assignment1.pdf in a directory called assignment1.
• Make a zip of the directory and submit that.