Here is the programming assignment specification that describes the assignment requirements.
Compilation: PASSED API: PASSED
SpotBugs: PASSED PMD: FAILED (1 warning) Checkstyle: FAILED (0 errors, 4 warnings)
Correctness: 38/38 tests passed Memory: 8/8 tests passed Timing: 20/20 tests passed
Aggregate score: 100.00% [Compilation: 5%, API: 5%, SpotBugs: 0%, PMD: 0%, Checkstyle: 0%, Correctness: 60%, Memory: 10%, Timing: 20%]
ASSESSMENT DETAILS
3.9K Dec 27 20:01 Percolation.java 2.3K Dec 27 20:01 PercolationStats.java
- COMPILING
% javac Percolation.java *-----------------------------------------------------------
% javac PercolationStats.java *-----------------------------------------------------------
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Checking the APIs of your programs. *----------------------------------------------------------- Percolation:
PercolationStats:
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- CHECKING STYLE AND COMMON BUG PATTERNS
% spotbugs *.class *-----------------------------------------------------------
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% pmd . *----------------------------------------------------------- PercolationStats.java:14: The private instance (or static) variable 'results' can be made 'final'; it is initialized only in the declaration or constructor. [ImmutableField] PMD ends with 1 warning.
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% checkstyle *.java *----------------------------------------------------------- [WARN] Percolation.java:120:13: The local variable 'N' must start with a lowercase letter and use camelCase. [LocalVariableName] [WARN] PercolationStats.java:13:23: The instance variable 'T' must start with a lowercase letter and use camelCase. [MemberName] [WARN] PercolationStats.java:66:13: The local variable 'T' must start with a lowercase letter and use camelCase. [LocalVariableName] Checkstyle ends with 0 errors and 3 warnings.
% custom checkstyle checks for Percolation.java *-----------------------------------------------------------
% custom checkstyle checks for PercolationStats.java *----------------------------------------------------------- [WARN] PercolationStats.java:7:1: The constant '1.96' appears more than once. Define a constant variable (such as 'CONFIDENCE_95') to hold the constant '1.96'. [NumericLiteralCount] Checkstyle ends with 0 errors and 1 warning.
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- TESTING CORRECTNESS
Testing correctness of Percolation *----------------------------------------------------------- Running 21 total tests.
Tests 1 through 7 create a Percolation object using your code, then repeatedly open sites by calling open(). After each call to open(), it checks the return values of isOpen(), percolates(), numberOfOpenSites(), and isFull() in that order. Tests 12 through 15 create a Percolation object using your code, then repeatedly call the methods open(), isOpen(), isFull(), percolates(), and, numberOfOpenSites() in random order with probabilities p = (p1, p2, p3, p4, p5). The tests stop immediately after the system percolates.
Tests 18 through 21 test backwash.
Except as noted, a site is opened at most once.
Test 1: open predetermined list of sites using file inputs
- filename = input6.txt
- filename = input8.txt
- filename = input8-no.txt
- filename = input10-no.txt
- filename = greeting57.txt
- filename = heart25.txt ==> passed
Test 2: open random sites until the system percolates
- n = 3
- n = 5
- n = 10
- n = 10
- n = 20
- n = 20
- n = 50
- n = 50 ==> passed
Test 3: open predetermined sites for n = 1 and n = 2 (corner case test)
- filename = input1.txt
- filename = input1-no.txt
- filename = input2.txt
- filename = input2-no.txt ==> passed
Test 4: check predetermined sites with long percolating path
- filename = snake13.txt
- filename = snake101.txt ==> passed
Test 5: open every site
- filename = input5.txt ==> passed
Test 6: open random sites until the system percolates, allowing open() to be called on a site more than once
- n = 3
- n = 5
- n = 10
- n = 10
- n = 20
- n = 20
- n = 50
- n = 50 ==> passed
Test 7: open random sites with large n
- n = 250
- n = 500
- n = 1000
- n = 2000 ==> passed
Test 8: call methods with invalid arguments
- n = 10, (row, col) = (-1, 5)
- n = 10, (row, col) = (11, 5)
- n = 10, (row, col) = (0, 5)
- n = 10, (row, col) = (5, -1)
- n = 10, (row, col) = (5, 11)
- n = 10, (row, col) = (5, 0)
- n = 10, (row, col) = (-2147483648, -2147483648)
- n = 10, (row, col) = (2147483647, 2147483647) ==> passed
Test 9: call constructor with invalid argument
- n = -10
- n = -1
- n = 0 ==> passed
Test 10: create multiple Percolation objects at the same time (to make sure you didn't store data in static variables) ==> passed
Test 11: open predetermined list of sites using file inputs, but permute the order in which methods are called
- filename = input8.txt; order = isFull(), isOpen(), percolates()
- filename = input8.txt; order = isFull(), percolates(), isOpen()
- filename = input8.txt; order = isOpen(), isFull(), percolates()
- filename = input8.txt; order = isOpen(), percolates(), isFull()
- filename = input8.txt; order = percolates(), isOpen(), isFull()
- filename = input8.txt; order = percolates(), isFull(), isOpen() ==> passed
Test 12: call open(), isOpen(), and numberOfOpenSites() in random order until just before system percolates
- n = 3, trials = 40, p = (0.4, 0.4, 0.0, 0.0, 0.3)
- n = 5, trials = 20, p = (0.4, 0.4, 0.0, 0.0, 0.3)
- n = 7, trials = 10, p = (0.4, 0.4, 0.0, 0.0, 0.3)
- n = 10, trials = 5, p = (0.4, 0.4, 0.0, 0.0, 0.3)
- n = 20, trials = 2, p = (0.4, 0.4, 0.0, 0.0, 0.3)
- n = 50, trials = 1, p = (0.4, 0.4, 0.0, 0.0, 0.3) ==> passed
Test 13: call open() and percolates() in random order until just before system percolates
- n = 3, trials = 40, p = (0.5, 0.0, 0.0, 0.5, 0.0)
- n = 5, trials = 20, p = (0.5, 0.0, 0.0, 0.5, 0.0)
- n = 7, trials = 10, p = (0.5, 0.0, 0.0, 0.5, 0.0)
- n = 10, trials = 5, p = (0.5, 0.0, 0.0, 0.5, 0.0)
- n = 20, trials = 2, p = (0.5, 0.0, 0.0, 0.5, 0.0)
- n = 50, trials = 1, p = (0.5, 0.0, 0.0, 0.5, 0.0) ==> passed
Test 14: call open() and isFull() in random order until just before system percolates
- n = 3, trials = 40, p = (0.5, 0.0, 0.5, 0.0, 0.0)
- n = 5, trials = 20, p = (0.5, 0.0, 0.5, 0.0, 0.0)
- n = 7, trials = 10, p = (0.5, 0.0, 0.5, 0.0, 0.0)
- n = 10, trials = 5, p = (0.5, 0.0, 0.5, 0.0, 0.0)
- n = 20, trials = 2, p = (0.5, 0.0, 0.5, 0.0, 0.0)
- n = 50, trials = 1, p = (0.5, 0.0, 0.5, 0.0, 0.0) ==> passed
Test 15: call all methods in random order until just before system percolates
- n = 3, trials = 40, p = (0.2, 0.2, 0.2, 0.2, 0.2)
- n = 5, trials = 20, p = (0.2, 0.2, 0.2, 0.2, 0.2)
- n = 7, trials = 10, p = (0.2, 0.2, 0.2, 0.2, 0.2)
- n = 10, trials = 5, p = (0.2, 0.2, 0.2, 0.2, 0.2)
- n = 20, trials = 2, p = (0.2, 0.2, 0.2, 0.2, 0.2)
- n = 50, trials = 1, p = (0.2, 0.2, 0.2, 0.2, 0.2) ==> passed
Test 16: call all methods in random order until almost all sites are open (with inputs not prone to backwash)
- n = 3
- n = 5
- n = 7
- n = 10
- n = 20
- n = 50 ==> passed
Test 17: substitute WeightedQuickUnionUF data type that sets root nondeterministically; call all methods in random order until almost all sites are open (with inputs not prone to backwash)
- n = 3
- n = 5
- n = 7
- n = 10
- n = 20
- n = 50 ==> passed
Test 18: check for backwash with predetermined sites
- filename = input20.txt
- filename = input10.txt
- filename = input50.txt
- filename = jerry47.txt
- filename = sedgewick60.txt
- filename = wayne98.txt ==> passed
Test 19: check for backwash with predetermined sites that have multiple percolating paths
- filename = input3.txt
- filename = input4.txt
- filename = input7.txt ==> passed
Test 20: call all methods in random order until all sites are open (these inputs are prone to backwash)
- n = 3
- n = 5
- n = 7
- n = 10
- n = 20
- n = 50 ==> passed
Test 21: substitute WeightedQuickUnionUF data type that sets root nondeterministically; call all methods in random order until all sites are open (these inputs are prone to backwash)
- n = 3
- n = 5
- n = 7
- n = 10
- n = 20
- n = 50 ==> passed
Total: 21/21 tests passed!
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- TESTING CORRECTNESS (substituting reference Percolation)
Testing correctness of PercolationStats *----------------------------------------------------------- Running 17 total tests.
Test 1: check formatting of output of main() % java-algs4 PercolationStats 20 10 mean =0.5887499999999999 stddev =0.06651284337128682 95% confidence interval = [0.5475249125733693, 0.6299750874266304]
% java-algs4 PercolationStats 200 100 mean =0.5908947499999999 stddev =0.010109769561836431 95% confidence interval = [0.58891323516588, 0.5928762648341198]
==> passed
Test 2: check that methods in PercolationStats do not print to standard output
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 3: check that mean() returns value in expected range
- n = 2, trials = 10000
- n = 5, trials = 10000
- n = 10, trials = 10000
- n = 25, trials = 10000 ==> passed
Test 4: check that stddev() returns value in expected range
- n = 2, trials = 10000
- n = 5, trials = 10000
- n = 10, trials = 10000
- n = 25, trials = 10000 ==> passed
Test 5: check that PercolationStats constructor creates trials Percolation objects, each of size n-by-n
- n = 15, trials = 15
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 6: check that PercolationStats.main() creates trials Percolation objects, each of size n-by-n
- n = 15, trials = 15
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 7: check that PercolationStats calls open() until system percolates
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 8: check that PercolationStats does not call open() after system percolates
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 9: check that mean() is consistent with the number of intercepted calls to open() on blocked sites
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 10: check that stddev() is consistent with the number of intercepted calls to open() on blocked sites
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 11: check that confidenceLo() and confidenceHigh() are consistent with mean() and stddev()
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 12: check that exception is thrown if either n or trials is out of bounds
- n = -23, trials = 42
- n = 23, trials = 0
- n = -42, trials = 0
- n = 42, trials = -1
- n = -2147483648, trials = -2147483648 ==> passed
Test 13: create two PercolationStats objects at the same time and check mean() (to make sure you didn't store data in static variables)
- n1 = 50, trials1 = 10, n2 = 50, trials2 = 5
- n1 = 50, trials1 = 5, n2 = 50, trials2 = 10
- n1 = 50, trials1 = 10, n2 = 25, trials2 = 10
- n1 = 25, trials1 = 10, n2 = 50, trials2 = 10
- n1 = 50, trials1 = 10, n2 = 15, trials2 = 100
- n1 = 15, trials1 = 100, n2 = 50, trials2 = 10 ==> passed
Test 14: check that the methods return the same value, regardless of the order in which they are called
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 15: check that no calls to StdRandom.setSeed()
- n = 20, trials = 10
- n = 20, trials = 10
- n = 40, trials = 10
- n = 80, trials = 10 ==> passed
Test 16: check distribution of number of sites opened until percolation
- n = 2, trials = 100000
- n = 3, trials = 100000
- n = 4, trials = 100000 ==> passed
Test 17: check that each site is opened the expected number of times
- n = 2, trials = 100000
- n = 3, trials = 100000
- n = 4, trials = 100000 ==> passed
Total: 17/17 tests passed!
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- MEMORY (substituting reference Percolation)
Analyzing memory of PercolationStats *----------------------------------------------------------- Running 4 total tests.
Test 1a-1d: check memory usage as a function of T trials for n = 100 (max allowed: 8*T + 128 bytes)
T bytes
=> passed 16 184
=> passed 32 312
=> passed 64 568
=> passed 128 1080
==> 4/4 tests passed
Estimated student memory = 8.00 T + 56.00 (R^2 = 1.000)
Total: 4/4 tests passed!
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- TIMING (substituting reference Percolation)
Timing PercolationStats *----------------------------------------------------------- Running 4 total tests.
Test 1: Call PercolationStats constructor and instance methods and count calls to StdStats.mean() and StdStats.stddev().
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 2: Call PercolationStats constructor and instance methods and count calls to methods in StdRandom.
- n = 20, trials = 10
- n = 20, trials = 10
- n = 40, trials = 10
- n = 80, trials = 10 ==> passed
Test 3: Call PercolationStats constructor and instance methods and count calls to methods in Percolation.
- n = 20, trials = 10
- n = 50, trials = 20
- n = 100, trials = 50
- n = 64, trials = 150 ==> passed
Test 4: Call PercolationStats constructor and instance methods with trials = 3 and values of n that go up by a multiplicative factor of sqrt(2). The test passes when n reaches 2,896.
The approximate order-of-growth is n ^ (log ratio)
n seconds log ratio
------------------------
724 0.15 2.5
1024 0.36 2.5
1448 1.01 2.9
2048 2.60 2.7
2896 6.43 2.6
==> passed
Total: 4/4 tests passed!
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- MEMORY
Analyzing memory of Percolation *----------------------------------------------------------- Running 4 total tests.
Test 1a-1d: check that total memory <= 17 n^2 + 128 n + 1024 bytes
n bytes
=> passed 64 72600
=> passed 256 1124952
=> passed 512 4477784
=> passed 1024 17868120
==> 4/4 tests passed
Estimated student memory = 17.00 n^2 + 41.00 n + 344.00 (R^2 = 1.000)
Test 2 (bonus): check that total memory <= 11 n^2 + 128 n + 1024 bytes
- failed memory test for n = 64 ==> FAILED
Total: 4/4 tests passed!
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- TIMING
Timing Percolation *----------------------------------------------------------- Running 16 total tests.
Test 1a-1e: Creates an n-by-n percolation system; open sites at random until the system percolates, interleaving calls to percolates() and open(). Count calls to connected(), union() and find().
2 * connected()
n union() + find() constructor
=> passed 16 339 294 2
=> passed 32 1575 1268 2
=> passed 64 6358 5096 2
=> passed 128 21140 18554 2
=> passed 256 93792 78312 2
=> passed 512 368049 310552 2
=> passed 1024 1475785 1243984 2
==> 7/7 tests passed
If one of the values in the table violates the performance limits the factor by which you failed the test appears in parentheses. For example, (9.6x) in the union() column indicates that it uses 9.6x too many calls.
Tests 2a-2f: Check whether the number of calls to union(), connected(), and find() is a constant per call to open(), isOpen(), isFull(), and percolates(). The table shows the maximum number of union() and find() calls made during a single call to open(), isOpen(), isFull(), and percolates(). One call to connected() counts as two calls to find().
n per open() per isOpen() per isFull() per percolates()
=> passed 16 8 0 2 2
=> passed 32 8 0 2 2
=> passed 64 8 0 2 2
=> passed 128 8 0 2 2
=> passed 256 8 0 2 2
=> passed 512 8 0 2 2
=> passed 1024 8 0 2 2
==> 7/7 tests passed
Running time (in seconds) depends on the machine on which the script runs.
Test 3: Create an n-by-n percolation system; interleave calls to percolates() and open() until the system percolates. The values of n go up by a factor of sqrt(2). The test is passed if n >= 4096 in under 10 seconds.
The approximate order-of-growth is n ^ (log ratio)
log union-find log
n seconds ratio operations ratio
-------------------------------------------
1024 0.16 2.5 4242324 2.0
1448 0.40 2.7 8389858 2.0
2048 1.00 2.6 16714448 2.0
2896 2.59 2.7 33671506 2.0
4096 5.83 2.3 66648554 2.0
==> passed
Test 4: Create an n-by-n percolation system; interleave calls to open(), percolates(), isOpen(), isFull(), and numberOfOpenSites() until. the system percolates. The values of n go up by a factor of sqrt(2). The test is passed if n >= 4096 in under 10 seconds.
log union-find log
n seconds ratio operations ratio
-------------------------------------------
1024 0.17 1.6 5460652 2.0
1448 0.54 3.3 10902124 2.0
2048 1.20 2.3 21805110 2.0
2896 2.82 2.5 43414096 2.0
4096 6.07 2.2 87001982 2.0
==> passed
Total: 16/16 tests passed!
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