CS 122, Winter 2020, Instructor:  Jeffrey Horn

CLASS ANNOUNCEMENTS (Thursday, February 6, 2020)

• What IS New:
  
  • A3 due date is pushed back two days to Friday Feb, 7, 2020.   See below.
  • Added a link to Java Docs in Lecture Notes below.
    
• What Was New :
• A3 is up.   See below.
• A2 due date is extended to Wed. Jan. 28, 2020 (11:59pm, which is basically midnight!)
• Reminder:  No class today!  (Tuesday, 1-21-2020)  I will be posting material (including video lectures) for you to review on your own time.   We will meet again this Thursday at our usual class time (3pm Th. 1-23-2020)
• Assignment 2 is up.  There is a short video that goes with it.  Look here.
  
• If you have not yet sent me your Assignment 1 java code then please do so.  (It was due Jan. 20)
• Welcome to class!  Check out our syllabus (link is below)
• This is where old announcements will go, so that you won't miss any news!

CONTENTS:

• Administrativa
  
• Lecture Notes
• Assignments
  
• Tests and Quizes

ADMINISTRATIVA

• Syllabus
• Handout Cabinet (where extra copies of printed handouts can be found...)

LECTURE NOTES

• JAVA Docs:   https://docs.oracle.com/javase/7/docs/api/

ASSIGNMENTS
 

• ASSIGNMENT 1:   Finding a Perfect Square Pyramid
  • HANDED OUT:   Tuesday, January 14, 2020
    
  • DUE ON:   Monday, January 20, 2020  (midnight)
  • GOAL:
    
  •  Consider a pyramid of spheres, D levels deep.  On the top level, level 1, there is one sphere.  Level 2 has four spheres, in a 2 by 2 grid (and level 1's sphere is nested in the middle of it).  Level 3 consists of nine spheres in a 3 by 3 grid wit level 2's grid centered on it.  Level 4 has 16 spheres in a 4x4 grid.  And so on!   The bottom level, level D, has D² spheres in a DxD grid.  So the total number of spheres, N,  in the pyramid is N=1+4+9+16+...+D²; a sum of perfect squares from 1 to D!
  • Write a program that finds the depth D' for a pyramid P' such that the total number of spheres in P' (N') is itself a perfect square!   (Note:  there are only two such depths and one of them is the trivial case D'=1.   Find the OTHER such D'!)
  • Your program should:
  1. Print out both the number of spheres N' and the depth D'.
  2. Calculate these numbers so that I can plainly see HOW you computed the numbers when I look are your code.   I say this because you might find a way to calculate D' and N' mathematically.  If you do then I want your code to include the formulae you used.  In other words, if you find the numbers by some other means (e.g., from a friend, or from the web) then I don't want your code to just print the numbers!  I want to see the calculation or computation IN THE CODE!
     
  • SUBMISSION:  Email me a copy of jour .java source code file as an attachment.   (Please write "CS 122:  A1" in the SUBJECT field.)
  
  
• ASSIGNMENT 2:   Let's Make a Deal!
• HANDED OUT:   Tuesday, January 21, 2020
  
• DUE ON:   Monday, January 27, 2020  (11:59pm)  Wednesday, January 29, 2020 (11:59pm)
  
• GOAL:  Design a software experiment to test the hypothesis that the SWITCH strategy wins the Let's Make a Deal!" game 2/3 of the time while the STAY strategy wins 1/3 of the time.
  
• STEPS:
  
1. Consider the famous problem known as "Let's Make a Deal!" or "The Monty Hall Problem."  Here is my own short video to introduce it (old, I know!).   Feel free to google "The Monty Hall Problem" and find out the fascinating history of this problem.
2. What is so interesting about this problem is that statistical analysis says that the best strategy is to switch doors rather than stay with your original choice (2/3 chance of winning the car versus 1/3).   But this result seems to most (including me!) counter-intuitive, at first.
3. Your challenge is not to perform a statistical analysis but instead to program an experiment that actually runs the game N times for both the SWITCH and the STAY strategies, and then prints the results.   Thus your simulation should experimentally verify the results predicted by the mathematics.  
   
4. Exactly how you do this is up to you.  Here is what I require:
• Your code must print out three numbers (all labeled!):  N (the total number of games simulated), percent of games that SWITCH strategy won the car, percent of games that STAY strategy won the car.  (That's one int and two floats!)
• Your code must use random numbers.   These can be from a pseudo random number generator like what Math.random() uses.
• I want to be able to be able to read and understand your code well enough that I can use it as (empirical) proof (or at least as evidence) that SWITCH is better than STAY.  You don't have to go crazy documenting your code.  Your target audience is me.  But I want to be sure that your program implements a valid experiment to test the hypothesis!  (that is, the hypothesis that SWITCH should win about 2/3 of the time STAY about 1/3, in the long run, as N approaches infinity!)
  
• SUBMISSION:  Email me a copy of jour .java source code file as an attachment.   (Please write "CS 122:  A2" in the SUBJECT field.)
  

• ASSIGNMENT 3:   Arrays of Integers
• HANDED OUT:   Tuesday, January 28, 2020
  
• DUE ON:   Wednesday, Feb. 5 , 2020 (11:59pm)  Friday, Feb. 7 , 2020 (11:59pm)
• GOAL:  Review arrays, learn basic file input, develop more algorithmic thinking.
  
• STEPS:
  
1. Grab this code we worked on together in class:   ReadIntegersFromFileToArray.java
   
2. Modify the code to do the following:   (Note:   Total is 200 pt.s)
1. Print the largest, smallest, and average values in the file, and the number of values.  (40 pt.s)
   
2. Print the two largest values.   (20 pt.s)
3. Print the five largest values.  (20 pt.s)
4. Print the k largest values (where k is the FIRST integer in the file).  (60 pt.s)
5. Do all of the above in a SINGLE PASS through your array.  (50 pt.s)
6. Use good style:   a main comment (5 pt.s) and indentation (5 pt.s)
   
3. Print to the console window.   Make sure all of your output val.s are LABELED!  (e.g., "Max:  529")
   
• SUBMISSION:  Email me a copy of jour .java source code file as an attachment.   (Please write "CS 122:  A3" in the SUBJECT field.)
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