feat(algorithms, dynamic programming): dynamic programming problems #151
Conversation
BrianLusina
added
enhancement
Algorithm
📝 WalkthroughWalkthroughReorganizes palindromic substring content into a new Dynamic Programming subsection, adds DP implementations and tests for counting palindromic substrings, introduces a longest-palindrome test, adds a new heap-based Schedule Tasks module and tests, and makes small documentation formatting updates. Changes
Estimated code review effort🎯 3 (Moderate) | ⏱️ ~25 minutes Suggested labels
Poem
🚥 Pre-merge checks | ❌ 3❌ Failed checks (1 warning, 2 inconclusive)
✏️ Tip: You can configure your own custom pre-merge checks in the settings. ✨ Finishing touches
Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out. Comment |
![coderabbitai[bot]](https://avatars.githubusercontent.com/in/347564?s=60&v=4){kind=small}
There was a problem hiding this comment.
Actionable comments posted: 2
Caution
Some comments are outside the diff and can’t be posted inline due to platform limitations.
⚠️ Outside diff range comments (1)
algorithms/dynamic_programming/palindromic_substring/longest_palindromic_substring.py (1)
32-32: Critical bug:i + ishould bei + 1.When setting the result bounds for a two-character palindrome, the end index calculation is incorrect. For
phrase[i] == phrase[i + 1], the palindrome spans indices[i, i + 1], not[i, i + i].Example: For input
"aa", wheni=0:
- Current:
result = [0, 0]→ returns"a"- Expected:
result = [0, 1]→ returns"aa"🐛 Proposed fix
if phrase[i] == phrase[i + 1]: dp[i][i + 1] = True - result = [i, i + i] + result = [i, i + 1]
🤖 Fix all issues with AI agents
In @algorithms/dynamic_programming/palindromic_substring/README.md:
- Around line 68-69: Update the sentence that currently reads "lengths greater
than three" to "lengths greater than two" in the README explanation so it
correctly matches the algorithm description (base cases for lengths 1 and 2,
loop starts at length 3); ensure the surrounding text still reads naturally
after this single-word change.
In
@algorithms/dynamic_programming/palindromic_substring/test_longest_palindromic_substring.py:
- Around line 7-15: Add missing edge-case tests to
LONGEST_PALINDROMIC_SUBSTRING_TEST_CASES by including ("", ""), ("a", "a"), and
a length-2 palindrome case such as ("aab", "aa"); also fix the off-by-one bug in
longest_palindromic_substring.py where the center-expansion result is set with
result = [i, i + i] — change it to result = [i, i + 1] so two-character
palindromes are handled correctly (search for the variable name result and the
incorrect assignment to locate the fix).
🧹 Nitpick comments (1)
algorithms/dynamic_programming/palindromic_substring/__init__.py (1)
34-66: Consider documenting the difference between the two implementations.Both functions produce identical results but use slightly different iteration patterns. The second function uses boolean arithmetic (
count += dp[i][j]) which is a nice Pythonic touch.It would be helpful to add a brief note in the docstring or a module-level comment explaining why two implementations exist (e.g., for educational purposes, different iteration order, etc.).
📝 Suggested docstring enhancement
def count_palindromic_substrings_2(s: str) -> int: """ Counts the number of palindromic substrings that can be found in the given string + + This is an alternative implementation that iterates by substring length + rather than by difference between indices. Both approaches have the same + O(n²) time and space complexity. + Args: s(str): string to check for palindromic substrings Returns: int: number of palindromic substrings """
📜 Review details
Configuration used: defaults
Review profile: CHILL
Plan: Pro
⛔ Files ignored due to path filters (19)
algorithms/dynamic_programming/palindromic_substring/images/examples/palindromic_substring_example_1.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/examples/palindromic_substring_example_2.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_1.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_10.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_11.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_12.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_13.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_14.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_15.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_16.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_17.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_2.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_3.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_4.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_5.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_6.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_7.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_8.pngis excluded by!**/*.pngalgorithms/dynamic_programming/palindromic_substring/images/solutions/palindromic_substring_solution_9.pngis excluded by!**/*.png
📒 Files selected for processing (10)
DIRECTORY.mdalgorithms/dynamic_programming/palindromic_substring/README.mdalgorithms/dynamic_programming/palindromic_substring/__init__.pyalgorithms/dynamic_programming/palindromic_substring/longest_palindromic_substring.pyalgorithms/dynamic_programming/palindromic_substring/test_longest_palindromic_substring.pyalgorithms/dynamic_programming/palindromic_substring/test_palindromic_substring.pyalgorithms/dynamic_programming/pascals_triangle/README.mdalgorithms/dynamic_programming/pascals_triangle/__init__.pyalgorithms/dynamic_programming/pascals_triangle/test_pascals_triangle.pyalgorithms/two_pointers/palindrome/README.md
💤 Files with no reviewable changes (1)
- algorithms/two_pointers/palindrome/README.md
🧰 Additional context used
🧬 Code graph analysis (1)
algorithms/dynamic_programming/palindromic_substring/test_longest_palindromic_substring.py (1)
algorithms/dynamic_programming/palindromic_substring/longest_palindromic_substring.py (1)
longest_palindromic_substring(4-42)
🪛 LanguageTool
algorithms/dynamic_programming/palindromic_substring/README.md
[style] ~23-~23: Consider a more expressive alternative.
Context: ...results of the earlier computations. To do this, we can create a lookup table, dp,...
(DO_ACHIEVE)
[style] ~43-~43: Using many exclamation marks might seem excessive (in this case: 15 exclamation marks for a text that’s 5567 characters long)
Context: ...s/palindromic_substring_solution_1.png) 
🪛 markdownlint-cli2 (0.18.1)
algorithms/dynamic_programming/palindromic_substring/README.md
23-23: Reference links and images should use a label that is defined
Missing link or image reference definition: "j"
(MD052, reference-links-images)
24-24: Reference links and images should use a label that is defined
Missing link or image reference definition: "j"
(MD052, reference-links-images)
33-33: Reference links and images should use a label that is defined
Missing link or image reference definition: "i+1"
(MD052, reference-links-images)
34-34: Reference links and images should use a label that is defined
Missing link or image reference definition: "i+1"
(MD052, reference-links-images)
38-38: Reference links and images should use a label that is defined
Missing link or image reference definition: "1"
(MD052, reference-links-images)
40-40: Reference links and images should use a label that is defined
Missing link or image reference definition: "2"
(MD052, reference-links-images)
DIRECTORY.md
72-72: Unordered list indentation
Expected: 2; Actual: 4
(MD007, ul-indent)
73-73: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
74-74: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
75-75: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
76-76: Unordered list indentation
Expected: 2; Actual: 4
(MD007, ul-indent)
77-77: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
🔇 Additional comments (7)
algorithms/dynamic_programming/pascals_triangle/__init__.py (1)
32-32: LGTM!Minor docstring formatting improvement - using
...instead of......for the sequence representation is cleaner and more conventional.algorithms/dynamic_programming/palindromic_substring/test_palindromic_substring.py (1)
1-34: LGTM!Well-structured test module with comprehensive parameterized test cases covering:
- Single character strings (each char is a palindrome)
- All same characters (
"aaa","zzz","wwwwwwwwww")- Mixed strings with various palindromic patterns
- Known palindrome word (
"tattarrattat")The test values are mathematically correct (e.g.,
"wwwwwwwwww"with 10 chars yields 55 palindromic substrings = n*(n+1)/2).DIRECTORY.md (1)
72-77: LGTM!The new directory entries correctly document the added palindromic substring and Pascal's triangle files. The indentation follows the existing pattern used throughout the file.
algorithms/dynamic_programming/palindromic_substring/longest_palindromic_substring.py (1)
1-1: Import path is correct.The
is_palindromefunction is properly exported fromalgorithms.two_pointers.palindrome(defined in__init__.pyat line 1). The import statement is valid and will work as intended.algorithms/dynamic_programming/palindromic_substring/README.md (1)
15-16: All referenced images are present in the repository. The image files at./images/examples/(example_1.png, example_2.png) and./images/solutions/(solution_1.png through solution_17.png) have been included in the PR.algorithms/dynamic_programming/palindromic_substring/test_longest_palindromic_substring.py (1)
18-22: LGTM!The test class structure and parameterized test method are well-implemented. Using
@parameterized.expandis the right approach for data-driven tests.algorithms/dynamic_programming/palindromic_substring/__init__.py (1)
1-31: LGTM!The DP implementation is correct. The algorithm properly:
- Initializes all single-character substrings as palindromes
- Checks adjacent pairs for length-2 palindromes
- Expands to longer lengths using the recurrence relation
dp[i][j] = (s[i] == s[j]) and dp[i+1][j-1]Time complexity is O(n²) and space complexity is O(n²), which is appropriate for this DP approach.
| 3. After these base cases, the algorithm checks all possible substrings of lengths greater than three. However, it only | ||
| compares the first and last characters, and the rest of the substring is checked using the lookup table. |
There was a problem hiding this comment.
Minor text inconsistency: "three" should be "two".
The solution summary states "lengths greater than three" but should say "lengths greater than two" to be consistent with the algorithm description. Base cases handle lengths 1 and 2, so the loop checks lengths starting from 3 (i.e., greater than 2).
📝 Suggested fix
-3. After these base cases, the algorithm checks all possible substrings of lengths greater than three. However, it only
+3. After these base cases, the algorithm checks all possible substrings of lengths greater than two. However, it only📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| 3. After these base cases, the algorithm checks all possible substrings of lengths greater than three. However, it only | |
| compares the first and last characters, and the rest of the substring is checked using the lookup table. | |
| 3. After these base cases, the algorithm checks all possible substrings of lengths greater than two. However, it only | |
| compares the first and last characters, and the rest of the substring is checked using the lookup table. |
🤖 Prompt for AI Agents
In @algorithms/dynamic_programming/palindromic_substring/README.md around lines
68 - 69, Update the sentence that currently reads "lengths greater than three"
to "lengths greater than two" in the README explanation so it correctly matches
the algorithm description (base cases for lengths 1 and 2, loop starts at length
3); ensure the surrounding text still reads naturally after this single-word
change.
| LONGEST_PALINDROMIC_SUBSTRING_TEST_CASES = [ | ||
| ("mnm", "mnm"), | ||
| ("zzz", "zzz"), | ||
| ("cat", "c"), | ||
| ("lever", "eve"), | ||
| ("xyxxyz", "yxxy"), | ||
| ("wwwwwwwwww", "wwwwwwwwww"), | ||
| ("tattarrattat", "tattarrattat"), | ||
| ] |
There was a problem hiding this comment.
Add edge cases for empty string, single character, and length-2 palindromes.
The test suite is missing edge cases that could expose bugs in the implementation:
- Empty string
"" - Single character
"a" - String where the longest palindrome is exactly 2 characters (e.g.,
"aab"→"aa")
The last case is particularly important because the implementation in longest_palindromic_substring.py has a bug on line 29: result = [i, i + i] should be result = [i, i + 1]. This bug would cause incorrect results when the longest palindrome is exactly 2 characters, but none of the current test cases would catch it.
🧪 Suggested additional test cases
LONGEST_PALINDROMIC_SUBSTRING_TEST_CASES = [
+ ("", ""),
+ ("a", "a"),
+ ("aab", "aa"),
+ ("baa", "aa"),
("mnm", "mnm"),
("zzz", "zzz"),
("cat", "c"),
("lever", "eve"),
("xyxxyz", "yxxy"),
("wwwwwwwwww", "wwwwwwwwww"),
("tattarrattat", "tattarrattat"),
]📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| LONGEST_PALINDROMIC_SUBSTRING_TEST_CASES = [ | |
| ("mnm", "mnm"), | |
| ("zzz", "zzz"), | |
| ("cat", "c"), | |
| ("lever", "eve"), | |
| ("xyxxyz", "yxxy"), | |
| ("wwwwwwwwww", "wwwwwwwwww"), | |
| ("tattarrattat", "tattarrattat"), | |
| ] | |
| LONGEST_PALINDROMIC_SUBSTRING_TEST_CASES = [ | |
| ("", ""), | |
| ("a", "a"), | |
| ("aab", "aa"), | |
| ("baa", "aa"), | |
| ("mnm", "mnm"), | |
| ("zzz", "zzz"), | |
| ("cat", "c"), | |
| ("lever", "eve"), | |
| ("xyxxyz", "yxxy"), | |
| ("wwwwwwwwww", "wwwwwwwwww"), | |
| ("tattarrattat", "tattarrattat"), | |
| ] |
🤖 Prompt for AI Agents
In
@algorithms/dynamic_programming/palindromic_substring/test_longest_palindromic_substring.py
around lines 7 - 15, Add missing edge-case tests to
LONGEST_PALINDROMIC_SUBSTRING_TEST_CASES by including ("", ""), ("a", "a"), and
a length-2 palindrome case such as ("aab", "aa"); also fix the off-by-one bug in
longest_palindromic_substring.py where the center-expansion result is set with
result = [i, i + i] — change it to result = [i, i + 1] so two-character
palindromes are handled correctly (search for the variable name result and the
incorrect assignment to locate the fix).
There was a problem hiding this comment.
Actionable comments posted: 2
🤖 Fix all issues with AI agents
In `@algorithms/heap/schedule_tasks/README.md`:
- Line 16: The constraint uses inconsistent notation `tasksi.start` and
`tasksi.end`; change them to consistent, standard subscript/index notation such
as `tasks[i].start` and `tasks[i].end` (or `tasks_i.start`/`tasks_i.end` if you
prefer subscripts) so the constraint reads "0 <= tasks[i].start < tasks[i].end
<= 10^4".
In `@algorithms/heap/schedule_tasks/test_schedule_tasks_on_minimum_machines.py`:
- Line 17: Update the failing test case tuple in
test_schedule_tasks_on_minimum_machines.py where the input intervals ([[5, 6],
[6, 7], [1, 7], [10, 14], [8, 13]], 4) has the wrong expected value; change the
expected value from 4 to 2 so the tuple becomes ([[5, 6], [6, 7], [1, 7], [10,
14], [8, 13]], 2) to match the algorithm's output.
🧹 Nitpick comments (2)
algorithms/heap/schedule_tasks/__init__.py (2)
9-11: Redundantheapifycall on an empty list.Calling
heapifyon an empty list is unnecessary since an empty list is already a valid heap. This is harmless but adds minor overhead.♻️ Suggested simplification
# initialize a min heap to keep track of the end times machines: List[int] = [] - heapify(machines)
5-22: Consider the side effect of in-place sorting.The function modifies the input
taskslist viatasks.sort(). While this is noted in the comment for performance reasons, callers may not expect their input to be mutated. Consider documenting this behavior in a docstring or usingsorted()if input immutability is preferred.Otherwise, the algorithm implementation is correct and efficient.
📜 Review details
Configuration used: defaults
Review profile: CHILL
Plan: Pro
⛔ Files ignored due to path filters (23)
algorithms/heap/schedule_tasks/images/examples/schedule_tasks_on_minimum_machines_example_1.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/examples/schedule_tasks_on_minimum_machines_example_2.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/examples/schedule_tasks_on_minimum_machines_example_3.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/examples/schedule_tasks_on_minimum_machines_example_4.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_1.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_10.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_11.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_12.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_13.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_14.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_15.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_16.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_17.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_18.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_19.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_2.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_3.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_4.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_5.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_6.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_7.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_8.pngis excluded by!**/*.pngalgorithms/heap/schedule_tasks/images/solutions/schedule_tasks_on_minimum_machines_solution_9.pngis excluded by!**/*.png
📒 Files selected for processing (5)
DIRECTORY.mdalgorithms/heap/__init__.pyalgorithms/heap/schedule_tasks/README.mdalgorithms/heap/schedule_tasks/__init__.pyalgorithms/heap/schedule_tasks/test_schedule_tasks_on_minimum_machines.py
🧰 Additional context used
🧬 Code graph analysis (2)
algorithms/heap/schedule_tasks/test_schedule_tasks_on_minimum_machines.py (1)
algorithms/heap/schedule_tasks/__init__.py (1)
minimum_machines(5-23)
algorithms/heap/schedule_tasks/__init__.py (2)
algorithms/sorting/heapsort/__init__.py (1)
heapify(60-63)puzzles/grade_school/__init__.py (1)
sort(15-19)
🪛 LanguageTool
algorithms/heap/schedule_tasks/README.md
[style] ~44-~44: Using many exclamation marks might seem excessive (in this case: 19 exclamation marks for a text that’s 4104 characters long)
Context: ...sks_on_minimum_machines_solution_1.png) 
🪛 markdownlint-cli2 (0.18.1)
DIRECTORY.md
72-72: Unordered list indentation
Expected: 2; Actual: 4
(MD007, ul-indent)
73-73: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
74-74: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
75-75: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
76-76: Unordered list indentation
Expected: 2; Actual: 4
(MD007, ul-indent)
77-77: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
140-140: Unordered list indentation
Expected: 0; Actual: 2
(MD007, ul-indent)
141-141: Unordered list indentation
Expected: 2; Actual: 4
(MD007, ul-indent)
142-142: Unordered list indentation
Expected: 4; Actual: 6
(MD007, ul-indent)
🔇 Additional comments (4)
algorithms/heap/schedule_tasks/README.md (1)
25-78: Documentation looks good!The solution explanation is clear, the algorithm steps are well-documented, and the time/space complexity analysis is accurate. The O(n log n) time complexity from sorting plus heap operations and O(n) space complexity for the heap are correctly stated.
algorithms/heap/schedule_tasks/test_schedule_tasks_on_minimum_machines.py (1)
6-16: Good test coverage for the algorithm.The test cases cover important scenarios:
- Overlapping intervals requiring multiple machines
- Non-overlapping sequential tasks (single machine)
- All tasks with identical time ranges (maximum machines)
- Tasks that can be chained (finish time equals next start time)
DIRECTORY.md (2)
72-77: New directory entries look correct.The Palindromic Substring and Pascals Triangle entries under Dynamic Programming are properly added and link to the correct file paths. The indentation follows the existing pattern in this file.
140-142: Heap section entry is correct.The new Heap section with Schedule Tasks entry correctly reflects the new module added in this PR.
✏️ Tip: You can disable this entire section by setting review_details to false in your review settings.
|
|
||
| - n == `tasks.length` | ||
| - 1 <= `tasks.length` <= 10^3 | ||
| - 0 <= `tasksi.start` < `tasksi.end` <= 10^4 |
There was a problem hiding this comment.
Minor typo in constraint notation.
The constraint tasksi.start and tasksi.end should use subscript notation consistently, such as tasks[i].start or tasks_i.start.
📝 Suggested fix
- - 0 <= `tasksi.start` < `tasksi.end` <= 10^4
+ - 0 <= `tasks[i].start` < `tasks[i].end` <= 10^4📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| - 0 <= `tasksi.start` < `tasksi.end` <= 10^4 | |
| - 0 <= `tasks[i].start` < `tasks[i].end` <= 10^4 |
🤖 Prompt for AI Agents
In `@algorithms/heap/schedule_tasks/README.md` at line 16, The constraint uses
inconsistent notation `tasksi.start` and `tasksi.end`; change them to
consistent, standard subscript/index notation such as `tasks[i].start` and
`tasks[i].end` (or `tasks_i.start`/`tasks_i.end` if you prefer subscripts) so
the constraint reads "0 <= tasks[i].start < tasks[i].end <= 10^4".
| ([[1, 3], [3, 5], [5, 9], [9, 12], [12, 13], [13, 16], [16, 17]], 1), | ||
| ([[1, 3], [2, 6], [5, 9], [4, 7], [8, 10], [8, 10], [12, 15]], 3), | ||
| ([[5, 6], [5, 6], [5, 6], [5, 6], [6, 7]], 4), | ||
| ([[5, 6], [6, 7], [1, 7], [10, 14], [8, 13]], 4), |
There was a problem hiding this comment.
🧩 Analysis chain
🏁 Script executed:
cd algorithms/heap/schedule_tasks && find . -type f -name "*.py" | head -20Repository: BrianLusina/PythonSnips
Length of output: 125
🏁 Script executed:
cd algorithms/heap/schedule_tasks && git ls-files | grep -E "(\.py$)" | head -20Repository: BrianLusina/PythonSnips
Length of output: 121
🏁 Script executed:
cat -n algorithms/heap/schedule_tasks/__init__.pyRepository: BrianLusina/PythonSnips
Length of output: 1060
🏁 Script executed:
cat -n algorithms/heap/schedule_tasks/test_schedule_tasks_on_minimum_machines.py | head -40Repository: BrianLusina/PythonSnips
Length of output: 1463
🏁 Script executed:
cd algorithms/heap/schedule_tasks && python3 << 'EOF'
from __init__ import minimum_machines
tasks = [[5, 6], [6, 7], [1, 7], [10, 14], [8, 13]]
result = minimum_machines(tasks.copy())
print(f"Tasks: {[[5, 6], [6, 7], [1, 7], [10, 14], [8, 13]]}")
print(f"Actual result: {result}")
print(f"Expected in test: 4")
print(f"Test passes: {result == 4}")
EOFRepository: BrianLusina/PythonSnips
Length of output: 153
🏁 Script executed:
cd algorithms/heap/schedule_tasks && python3 << 'EOF'
import sys
sys.path.insert(0, '/dev/null') # prevent import issues
from heapq import heappush, heappop, heapify
from typing import List
def minimum_machines(tasks: List[List[int]]) -> int:
tasks.sort(key=lambda x: x[0])
machines: List[int] = []
heapify(machines)
for current_task in tasks:
task_start, task_end = current_task
if machines and machines[0] <= task_start:
heappop(machines)
heappush(machines, task_end)
return len(machines)
# Test the problematic case
tasks = [[5, 6], [6, 7], [1, 7], [10, 14], [8, 13]]
result = minimum_machines(tasks)
print(f"Result: {result}")
print(f"Expected: 4")
EOFRepository: BrianLusina/PythonSnips
Length of output: 88
Fix incorrect expected value in test case at line 17.
The test case ([[5, 6], [6, 7], [1, 7], [10, 14], [8, 13]], 4) has an incorrect expected value. The algorithm returns 2 machines, not 4.
When sorted by start time: [[1,7], [5,6], [6,7], [8,13], [10,14]]
[1,7]: allocate machine, machines=[7][5,6]:7 > 5, allocate new machine, machines=[6,7][6,7]:6 <= 6, reuse machine, machines=[7,7][8,13]:7 <= 8, reuse machine, machines=[7,13][10,14]:7 <= 10, reuse machine, machines=[13,14]
Result: 2 machines.
Change the expected value from 4 to 2.
🤖 Prompt for AI Agents
In `@algorithms/heap/schedule_tasks/test_schedule_tasks_on_minimum_machines.py` at
line 17, Update the failing test case tuple in
test_schedule_tasks_on_minimum_machines.py where the input intervals ([[5, 6],
[6, 7], [1, 7], [10, 14], [8, 13]], 4) has the wrong expected value; change the
expected value from 4 to 2 so the tuple becomes ([[5, 6], [6, 7], [1, 7], [10,
14], [8, 13]], 2) to match the algorithm's output.
Describe your change:
Count number of palindromic substrings in a string
Checklist:
Fixes: #{$ISSUE_NO}.Summary by CodeRabbit
Documentation
New Features
Tests
Style
✏️ Tip: You can customize this high-level summary in your review settings.