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@codeflash-ai codeflash-ai bot commented May 13, 2025

📄 173,949% (1,739.49x) speedup for sorter in code_to_optimize/bubble_sort.py

⏱️ Runtime : 3.54 seconds 2.03 milliseconds (best of 488 runs)

📝 Explanation and details

Here’s an optimized version that replaces the O(n²) bubble sort with Python's highly-efficient built-in sort(), which runs in O(n log n) time and uses less memory by sorting in-place, while preserving all the comments and output.

This preserves the behavior and signature exactly while greatly improving performance.

Correctness verification report:

Test Status
⚙️ Existing Unit Tests 14 Passed
🌀 Generated Regression Tests 57 Passed
⏪ Replay Tests 🔘 None Found
🔎 Concolic Coverage Tests 🔘 None Found
📊 Tests Coverage 100.0%
⚙️ Existing Unit Tests Details
- benchmarks/test_benchmark_bubble_sort.py
- test_bubble_sort.py
- test_bubble_sort_conditional.py
- test_bubble_sort_import.py
- test_bubble_sort_in_class.py
- test_bubble_sort_parametrized.py
- test_bubble_sort_parametrized_loop.py
🌀 Generated Regression Tests Details
import random
import string
import sys

# imports
import pytest  # used for our unit tests
from code_to_optimize.bubble_sort import sorter

# unit tests

# -----------------
# BASIC TEST CASES
# -----------------

def test_sorter_empty_list():
    """Test sorting an empty list"""
    arr = []
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_single_element():
    """Test sorting a single-element list"""
    arr = [42]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_sorted_list():
    """Test sorting an already sorted list"""
    arr = [1, 2, 3, 4, 5]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_reverse_sorted_list():
    """Test sorting a reverse-sorted list"""
    arr = [5, 4, 3, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_unsorted_list():
    """Test sorting a typical unsorted list"""
    arr = [3, 1, 4, 1, 5, 9, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_with_duplicates():
    """Test sorting a list with duplicate elements"""
    arr = [2, 3, 2, 1, 3, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_negative_numbers():
    """Test sorting a list with negative numbers"""
    arr = [-3, -1, -2, 0, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_mixed_positive_negative():
    """Test sorting a list with both positive and negative numbers"""
    arr = [5, -10, 0, 7, -3]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_all_equal_elements():
    """Test sorting a list where all elements are the same"""
    arr = [7, 7, 7, 7]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

# -----------------
# EDGE TEST CASES
# -----------------

def test_sorter_large_negative_and_positive():
    """Test sorting a list with very large and very small integers"""
    arr = [sys.maxsize, -sys.maxsize-1, 0, 1, -1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_floats():
    """Test sorting a list of floats"""
    arr = [3.1, 2.4, 5.6, 1.0, 2.4]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_mixed_ints_and_floats():
    """Test sorting a list of mixed ints and floats"""
    arr = [3, 2.5, 1, 4.5, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_strings():
    """Test sorting a list of strings"""
    arr = ["banana", "apple", "cherry"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_strings_case_sensitive():
    """Test sorting a list of strings with different cases"""
    arr = ["banana", "Apple", "cherry"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_single_character_strings():
    """Test sorting a list of single-character strings"""
    arr = ['z', 'a', 'm', 'k']
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_empty_strings():
    """Test sorting a list containing empty strings"""
    arr = ["", "a", "b", ""]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_list_with_none_raises():
    """Test that sorting a list containing None raises TypeError"""
    arr = [1, None, 2]
    with pytest.raises(TypeError):
        sorter(arr.copy())

def test_sorter_list_with_unorderable_types_raises():
    """Test that sorting a list with incompatible types raises TypeError"""
    arr = [1, "a", 2]
    with pytest.raises(TypeError):
        sorter(arr.copy())

def test_sorter_list_of_lists_raises():
    """Test that sorting a list of lists of different lengths raises TypeError"""
    arr = [[1,2], [1], [1,2,3]]
    # Python can compare lists lexicographically, so this should not raise
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_list_of_tuples():
    """Test sorting a list of tuples"""
    arr = [(2, 3), (1, 2), (2, 2)]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_list_with_nan():
    """Test sorting a list with NaN values (should place NaN at the end in Python 3)"""
    arr = [3, float('nan'), 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_list_with_inf():
    """Test sorting a list with infinity values"""
    arr = [float('inf'), 1, float('-inf'), 0]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

# -----------------
# LARGE SCALE TEST CASES
# -----------------

def test_sorter_large_random_integers():
    """Test sorting a large list of random integers"""
    arr = random.sample(range(-100000, -99000), 1000)
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_large_sorted_input():
    """Test sorting a large already sorted list"""
    arr = list(range(1000))
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_large_reverse_sorted_input():
    """Test sorting a large reverse-sorted list"""
    arr = list(range(999, -1, -1))
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_large_duplicates():
    """Test sorting a large list with many duplicates"""
    arr = [random.choice([1, 2, 3, 4, 5]) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_large_strings():
    """Test sorting a large list of random strings"""
    arr = [''.join(random.choices(string.ascii_letters, k=5)) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorter_large_floats():
    """Test sorting a large list of random floats"""
    arr = [random.uniform(-10000, 10000) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output

# ---------------
# MUTATION TESTING: Corner cases to catch subtle bugs
# ---------------

def test_sorter_not_in_place():
    """Test that sorter does not return a new list but sorts in place (function returns the same list object)"""
    arr = [3, 2, 1]
    codeflash_output = sorter(arr); out = codeflash_output

def test_sorter_mutates_input():
    """Test that the input list is actually mutated (not just returned sorted copy)"""
    arr = [4, 2, 3]
    sorter(arr)

def test_sorter_stability():
    """Test that sorter is stable for equal elements (should preserve original order for equal elements)"""
    # For bubble sort, stability is preserved
    arr = [('a', 2), ('b', 1), ('c', 2), ('d', 1)]
    # Sort by second element
    def key(x): return x[1]
    arr_sorted = sorted(arr, key=key)
    # To simulate the same, we'll sort by the second element using a custom wrapper
    # But since our sorter does not support key, this is not applicable
    # So this test is not valid for this implementation
    pass  # Documented for completeness
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.

import random  # used for generating large random lists
import string  # used for string sorting tests
import sys  # used for edge case with large/small numbers

# imports
import pytest  # used for our unit tests
from code_to_optimize.bubble_sort import sorter

# unit tests

# ----------------
# Basic Test Cases
# ----------------

def test_empty_list():
    # Sorting an empty list should return an empty list
    arr = []
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_single_element():
    # Sorting a list with one element should return the same list
    arr = [42]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_sorted_list():
    # Sorting an already sorted list should not change it
    arr = [1, 2, 3, 4, 5]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_reverse_sorted_list():
    # Sorting a reverse sorted list should return a sorted list
    arr = [5, 4, 3, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_duplicates():
    # Sorting a list with duplicate elements
    arr = [3, 1, 2, 3, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_negative_numbers():
    # Sorting a list with negative and positive numbers
    arr = [-3, -1, 2, 0, -2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_floats():
    # Sorting a list with floats and integers
    arr = [3.2, 1.5, 2.7, 1, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_strings():
    # Sorting a list of strings
    arr = ["banana", "apple", "cherry"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_mixed_case_strings():
    # Sorting a list of strings with mixed cases
    arr = ["Banana", "apple", "Cherry"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

# ----------------
# Edge Test Cases
# ----------------

def test_all_equal_elements():
    # Sorting a list where all elements are the same
    arr = [7] * 10
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_alternating_order():
    # Sorting a list with alternating high/low values
    arr = [1, 100, 2, 99, 3, 98]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_large_and_small_numbers():
    # Sorting a list with very large and very small numbers
    arr = [sys.maxsize, -sys.maxsize-1, 0, 999999999, -999999999]
    codeflash_output = sorter(arr.copy()); result = codeflash_output
    expected = sorted(arr)

def test_list_with_none():
    # Sorting a list with None should raise TypeError
    arr = [1, None, 2]
    with pytest.raises(TypeError):
        sorter(arr.copy())

def test_list_with_unorderable_types():
    # Sorting a list with incompatible types should raise TypeError
    arr = [1, "a", 2]
    with pytest.raises(TypeError):
        sorter(arr.copy())

def test_unicode_strings():
    # Sorting a list with unicode strings
    arr = ["éclair", "apple", "Éclair", "banana"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_list_with_nan():
    # Sorting a list with float('nan') values
    arr = [3, float('nan'), 1, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_list_with_inf():
    # Sorting a list with inf and -inf
    arr = [float('inf'), 1, float('-inf'), 0]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_list_with_zero_and_negative_zero():
    # Sorting a list with 0.0 and -0.0
    arr = [0.0, -0.0, 1, -1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_list_with_custom_objects():
    # Sorting a list of objects with __lt__ defined
    class Box:
        def __init__(self, val):
            self.val = val
        def __lt__(self, other):
            return self.val < other.val
        def __eq__(self, other):
            return self.val == other.val
        def __repr__(self):
            return f"Box({self.val})"
    arr = [Box(3), Box(1), Box(2)]
    codeflash_output = sorter(arr.copy()); result = codeflash_output

# ----------------------
# Large Scale Test Cases
# ----------------------

def test_large_random_integers():
    # Sorting a large list of random integers
    arr = [random.randint(-10000, 10000) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_large_sorted_list():
    # Sorting a large already sorted list
    arr = list(range(1000))
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_large_reverse_sorted_list():
    # Sorting a large reverse sorted list
    arr = list(range(999, -1, -1))
    expected = list(range(1000))
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_large_list_with_duplicates():
    # Sorting a large list with many duplicates
    arr = [random.choice([1, 2, 3, 4, 5]) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_large_strings():
    # Sorting a large list of random strings
    arr = [
        ''.join(random.choices(string.ascii_letters, k=5))
        for _ in range(1000)
    ]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_large_list_all_equal():
    # Sorting a large list where all elements are the same
    arr = [42] * 1000
    codeflash_output = sorter(arr.copy()); result = codeflash_output

def test_large_list_alternating_pattern():
    # Sorting a large list with an alternating pattern
    arr = [i % 2 for i in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.

To edit these changes git checkout codeflash/optimize-sorter-man5gytu and push.

Codeflash

Here’s an optimized version that replaces the O(n²) bubble sort with Python's highly-efficient built-in `sort()`, which runs in O(n log n) time and uses less memory by sorting in-place, while preserving all the comments and output.


This preserves the behavior and signature exactly while greatly improving performance.
@codeflash-ai codeflash-ai bot added the ⚡️ codeflash Optimization PR opened by Codeflash AI label May 13, 2025
@codeflash-ai codeflash-ai bot requested a review from zomglings May 13, 2025 23:35
@zomglings zomglings closed this May 13, 2025
@codeflash-ai codeflash-ai bot deleted the codeflash/optimize-sorter-man5gytu branch May 13, 2025 23:36
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⚡️ codeflash Optimization PR opened by Codeflash AI

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