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@@ -8,6 +8,10 @@ and ideas.
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Remember, that you should design how the algorithm will work on paper before
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coding.
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Some sample code showing show to read in a line of numbers and store them as a
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list of ints can be found here:
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[cs412_reading_input.py](https://canvas.jmu.edu/courses/2112008/files/178177051?wrap=1)
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## Logarithmic Search in a Circularly Sorted List
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A list $A[0..(n-1)]$ is circularly sorted if there is an index $i$ such that the
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@@ -16,9 +20,9 @@ list. For example $\{7, 8, 10, 1, 2, 3, 4\}$ is circularly sorted, since the
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subarray $A[3..6]$ concatenated with the subarray $A[0..2]$ is the array
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$\{1, 2, 3, 4, 7, 8,
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10\}$, which is sorted. Your task is to write a recursive algorithm, which given
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a a circularly sorted array with no duplicate values and a query integer $q$
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a a circularly sorted array with **no duplicate** values and a query integer $q$
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determines and returns the index of $q$ in the array if it exists, or returns
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$-1$ otherwise. Your algorithm should run in $O(log n)$ time.
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$-1$ otherwise. **Your algorithm should run in $O(log n)$ time**.
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### Input
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@@ -48,4 +52,5 @@ if it exists, or -1 if it does not exist in the list.
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### Turning it in
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Save your solution `cs412_circular_sort_search.py` and turn it in to Gradescope.
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Save your solution **cs412_circular_sort_search.py** and turn it in to
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Gradescope.
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@@ -99,3 +99,65 @@ Your code will be checked for speed and a leaderboard posted within Gradescope.
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## Acknowledgments
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Problem from Kattis are used under their educational license.
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# Lab 3: Empirical Analysis with Profiling
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This lab is intended to be started in class, where additional background
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information may be provided.
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## Requirements
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You will need to use a UNIX based system can run shell scripts. **STU** would be
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a good resource.
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## Goal
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Utilize run-time profilers to identify poorly performing sections of a program
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and then potential these areas.
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## Process
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### Part 1
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Utilize the two programs from your "What does the Fox Say" homework. Run each of
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these with the profiling information from the lecture slides
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([cs412_03_EmpiricalAnalysis.pdf](https://canvas.jmu.edu/courses/2112008/files/178177075?wrap=1))
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and gather/analyze this information. For the dict version of the program,
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identify and try and to improve the portions of your program that take up the
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most time.
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### Part 2
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Using the large examples files from "What does the Fox Say" homework and the
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**split**, **wc**, **and head** UNIX commands, create input files of size 200K,
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400K, 600K, 800K. To find out more about these UNIX commands, you can use Google
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or the man pages from stu.
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Write a shell script that performs this work and then runs the dict version of
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your program capturing the execution time using the **time** UNIX command.
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Create a plot of this run time where the Y axis is the run time and the X axis
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is the input size. The shell script only needs to run your work and produce the
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plots (it does not need to do the file manipulation, you can do that on your
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own).
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An example python script for creating the plot is here:
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[line_plot.py](./line_plot.py)
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## Deliverables
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- A PDF (described below)
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- Python script to create your plot
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- Shell script to run your test cases
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> Eclypse's Note: Did not need to submit a Shell script
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Create a single PDF that contains the following information with two separate
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sections (one for your list and one for your _dict_ versions of the HW 1). Each
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section must showcase the results/output of 2 _cProfile_ runs. Then create a 3rd
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section within the PDF that discusses the slowest portions of the _dict_
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program. This discussion must include steps you tried in order to improve the
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run time performance of your program.
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For the 4th and final section, show the plot of your run times and discuss what
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type of growth rate is experienced by your program and what portion of the
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program you believe is responsible for this.
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63
Palindrome-Partitioning/README.md
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# Lab 4: Coding Palindrome Partitioning with Backtracking
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## Description
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In this lab you will develop a recursive algorithm for the palindrome partition
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counting problem.
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A **palindrome** is a string of letters that is the same backwards as forwards.
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For example, "racecar", "eevee", and "12321" are all palindromes. A string with
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a single character is trivially a palindrome.
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A **palindromic partition** of a string is a partition of the string into
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substrings whose concatenation is equal to the original string, but such that
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every substring is itself a palindrome.
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For example, the string, "seeks" can be broken up into the palindrome partition
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["s", "ee", "k", "s"] or as ["s", "e", "e", "k", "s"]. Your task is to design
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and implement a recursive algorithm that counts the number of palindromic
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partitions of a given string.
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## Input
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Your input will begin with a single line containing a nonnegative integer n
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followed by exactly n lines each of which contains an input string.
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## Output
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You should output **exactly** n lines, one for each input string with each
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ending in a newline character. The value of each line should be the number of
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unique palindromic partitions that can be made with the input string.
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<table>
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<tr>
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<td>Sample Input</td>
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<td>Sample Output</td>
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</tr>
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<tr>
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<td><pre>3<br>abc<br>bcccb<br>seeks</pre></td>
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<td><pre>1<br>5<br>2</pre></td>
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</tr>
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</table>
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## Turning it in
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**Submit your Python code as cs412_palindrome_count_bt.py to Gradescope.**
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## Hints
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- As always, when devising a recursive backtracking algorithm, think of your
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output as a series of choices. Almost always you can get to the recursive
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solution by having each recursive call brute-force make all possible next
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choice and use the recursion fairy to handle the remaining choices.
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- What are the choices here? Think about what you need to do to the string to
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turn it into a palindromic partition--this will tell you exactly what a
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"choice" is in terms of producing palindromic partitions.
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- Don't worry about speed here. You are almost certainly going to have a rather
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bad runtime. We'll fix this in a few weeks when we talk about dynamic
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programming. You probably want to write a tiny helper predicate
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isPalindrome(s) that returns true if s is a palindrome and false otherwise.
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- How can you easily have a string evaluate to the reverse of itself? Recall
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that slicing takes 3 values (start pos, end pos, step size). See this website
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for details:
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https://www.digitalocean.com/community/tutorials/how-to-index-and-slice-strings-in-python-3
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157
Recursive-Grid-Tiling/README.md
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# Coding 2: Recursive Grid Tiling
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## Grid Tiling
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Here's an interesting theorem: consider a square grid of squares with sides
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given by some power of (i.e. a grid of size $2^n \times 2^n$) like this example
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of a $2^3 \times 2^3$ grid:
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If you select exactly one grid square to remove (which is colored black below),
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then the remaining squares can be tiled by 3-square L-shape tiles, like this.
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The proof of this fact is inductive and leads to a simple recursive algorithm
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for producing a tiling. Assume that you can tile any $2^{n-1} \times 2^{n-1}$
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grid with a single square removed with L-shaped tiles. Suppose we are given a
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$2^n \times 2^n$ grid with one square removed.
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Here's an example of what we've got:
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How can we use our inductive hypothesis to show that the entire grid can be
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tiled? Well, let's start by splitting our grid vertically and horizontally in
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half:
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Notice that this splits our $2^n \times 2^n$ sized grid into four
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$2^{n-1} \times 2^{n-1}$ sized sub-grids, and one of them (the top left in our
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example above) already has a square removed _but notice that three of them do
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not yet have a square removed_. This means we can use our inductive hypothesis
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to tile whichever sub-grid contains the square we already wanted removed:
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But now we're a bit stuck, because the conditions of the inductive hypothesis
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apply if we have a $2^{n-1} \times 2^{n-1}$ grid with one square removed, but
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instead we have three $2^{n-1} \times 2^{n-1}$ grids with no squares removed.
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But now notice the following trick. We can place a single L-tile that covers
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exactly one grid square in each of three sub-grids that we haven't yet tiled!
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But notice that since this new L-tile covers exactly one square from each of the
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three untiled sub-grids, we now have three $2^{n-1} \times 2^{n-1}$ each with a
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single square removed and so the inductive hypothesis now applies! We can tile
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each quadrant individually using the inductive hypothesis.
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Then
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Then
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And finally, with the red dividing lines removed:
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The base case for this induction are the 2x2 grids, which become L-tiles if we
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remove anyone grid square.
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## Your Task
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You are going to write a program to compute L-tilings of $2^n \times 2^n$ square
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grids. You will assign each tile a number starting with 00. The first tile you
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generate should have all of its grid cells marked with a 00, the next tile 01,
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etc.
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### Input
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The first line of input will give the grid size parameter n as an integer. The
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second line will contain the index (i, j) of the removed tile.
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### Output
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Your code should output $2^n$ lines, each containing $2^n$ 2-digit numbers
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separated by spaces (and formatted so that single digit numbers have a leading
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0). The value of each grid location should be the tile index you generated. (You
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may assume you won't need 3 digits).
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<table>
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<tr>
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<td>Sample Input</td>
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<td>Sample Output</td>
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</tr>
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<tr>
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<td><pre>3<br>0 0</pre></td>
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<td>
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<pre>
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-1 02 03 03 07 07 08 08
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02 02 01 03 07 06 06 08
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04 01 01 05 09 09 06 10
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04 04 05 05 00 09 10 10
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12 12 13 00 00 17 18 18
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12 11 13 13 17 17 16 18
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14 11 11 15 19 16 16 20
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14 14 15 15 19 19 20 20</pre>
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</td>
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</tr>
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<tr>
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<td><pre>3<br>1 2</pre></td>
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<td>
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<pre>
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02 02 03 03 07 07 08 08
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02 01 -1 03 07 06 06 08
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04 01 01 05 09 09 06 10
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04 04 05 05 00 09 10 10
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12 12 13 00 00 17 18 18
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12 11 13 13 17 17 16 18
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14 11 11 15 19 16 16 20
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14 14 15 15 19 19 20 20</pre>
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</td>
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</tr>
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<tr>
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<td><pre>4<br>10 10</pre></td>
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<td>
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<pre>
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03 03 04 04 08 08 09 09 24 24 25 25 29 29 30 30
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03 02 02 04 08 07 07 09 24 23 23 25 29 28 28 30
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05 02 06 06 10 10 07 11 26 23 27 27 31 31 28 32
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05 05 06 01 01 10 11 11 26 26 27 22 22 31 32 32
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13 13 14 01 18 18 19 19 34 34 35 35 22 39 40 40
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13 12 14 14 18 17 17 19 34 33 33 35 39 39 38 40
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15 12 12 16 20 17 21 21 36 36 33 37 41 38 38 42
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15 15 16 16 20 20 21 00 00 36 37 37 41 41 42 42
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45 45 46 46 50 50 51 00 66 66 67 67 71 71 72 72
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45 44 44 46 50 49 51 51 66 65 65 67 71 70 70 72
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47 44 48 48 52 49 49 53 68 65 -1 69 73 73 70 74
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47 47 48 43 52 52 53 53 68 68 69 69 64 73 74 74
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55 55 56 43 43 60 61 61 76 76 77 64 64 81 82 82
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55 54 56 56 60 60 59 61 76 75 77 77 81 81 80 82
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57 54 54 58 62 59 59 63 78 75 75 79 83 80 80 84
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57 57 58 58 62 62 63 63 78 78 79 79 83 83 84 84</pre>
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</td>
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</tr>
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</table>
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## Visualizing Your Results:
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You can use the [plot_tiles.py](./plot_tiles.py) program to visualize your
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input. It will draw figures similar to the ones shown in this assignment and may
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help you debug your program if it has issues.
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## Program Grading and Submission
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This assignment is to be submitted into Gradescope. Grading criterion is:
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- 10 points for the example problems shown in the assignment
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- 8 points on hidden example problems
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- 2 points for style
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BIN
Recursive-Grid-Tiling/images/t0.png
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Recursive-Grid-Tiling/images/t1.png
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Recursive-Grid-Tiling/images/t8.png
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BIN
Recursive-Grid-Tiling/images/tiling.png
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After Width: | Height: | Size: 7.2 KiB |