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@codeflash-ai codeflash-ai bot commented Jun 18, 2025

📄 207,897% (2,078.97x) speedup for sorter in code_to_optimize/bubble_sort.py

⏱️ Runtime : 3.36 seconds 1.62 milliseconds (best of 579 runs)

📝 Explanation and details

Here is an optimized version of your program.
Your original code uses a naïve bubble sort, which is highly inefficient (O(n²)).
Python has a highly optimized built-in sort, Timsort, running in O(n log n).
Replacing the manual sort with list.sort() (in-place sort) maintains functionality and gives a huge performance boost.

All function signatures and return results are preserved, as are your print statements.
This change preserves the intended output and greatly improves speed, especially for large lists.

Correctness verification report:

Test Status
⚙️ Existing Unit Tests 20 Passed
🌀 Generated Regression Tests 53 Passed
⏪ Replay Tests 🔘 None Found
🔎 Concolic Coverage Tests 🔘 None Found
📊 Tests Coverage 100.0%
⚙️ Existing Unit Tests and Runtime
Test File::Test Function Original ⏱️ Optimized ⏱️ Speedup
benchmarks/test_benchmark_bubble_sort.py::test_sort2 6.92ms 16.9μs ✅40791%
test_bubble_sort.py::test_sort 832ms 138μs ✅602851%
test_bubble_sort_conditional.py::test_sort 6.21μs 3.21μs ✅93.5%
test_bubble_sort_import.py::test_sort 833ms 143μs ✅579460%
test_bubble_sort_in_class.py::TestSorter.test_sort_in_pytest_class 832ms 142μs ✅583202%
test_bubble_sort_parametrized.py::test_sort_parametrized 507ms 144μs ✅350473%
test_bubble_sort_parametrized_loop.py::test_sort_loop_parametrized 104μs 20.6μs ✅405%
🌀 Generated Regression Tests and Runtime
import random  # used for generating large random test cases
import string  # used for string-based test cases
import sys  # used for maxsize edge case

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

# unit tests

# ------------------------
# 1. Basic Test Cases
# ------------------------

def test_sorter_empty_list():
    # Test sorting an empty list
    arr = []
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 3.83μs -> 2.92μs (31.4% faster)

def test_sorter_single_element():
    # Test sorting a list with a single element
    arr = [42]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.04μs -> 2.96μs (36.6% faster)

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 # 4.67μs -> 3.08μs (51.3% faster)

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 # 5.12μs -> 2.96μs (73.2% faster)

def test_sorter_unsorted_list():
    # Test sorting a typical unsorted list
    arr = [3, 1, 4, 5, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.71μs -> 2.96μs (59.1% faster)

def test_sorter_with_duplicates():
    # Test sorting a list with duplicate values
    arr = [3, 1, 2, 3, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 5.17μs -> 2.96μs (74.6% faster)

def test_sorter_negative_numbers():
    # Test sorting a list with negative numbers
    arr = [0, -1, -3, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.88μs -> 3.04μs (60.3% faster)

def test_sorter_floats():
    # Test sorting a list with float values
    arr = [3.2, 1.5, 2.8, 1.2, 3.1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 6.71μs -> 3.62μs (85.0% faster)

def test_sorter_mixed_ints_floats():
    # Test sorting a list with both ints and floats
    arr = [2, 3.5, 1, 2.2, 3]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 6.00μs -> 3.42μs (75.6% faster)

# ------------------------
# 2. Edge Test Cases
# ------------------------

def test_sorter_all_equal_elements():
    # Test sorting a list where all elements are equal
    arr = [7, 7, 7, 7]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.38μs -> 2.88μs (52.2% faster)

def test_sorter_large_and_small_numbers():
    # Test 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 # 6.29μs -> 3.12μs (101% faster)
    expected = [-sys.maxsize - 1, -999999999, 0, 999999999, sys.maxsize]

def test_sorter_strings():
    # Test sorting a list of strings (lexicographical order)
    arr = ["banana", "apple", "cherry", "date"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 5.17μs -> 3.38μs (53.1% faster)

def test_sorter_case_sensitive_strings():
    # Test sorting a list of strings with different cases
    arr = ["banana", "Apple", "cherry", "Date"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.88μs -> 3.12μs (56.0% faster)

def test_sorter_empty_strings():
    # Test sorting a list with empty strings
    arr = ["", "a", "abc", "", "b"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 5.29μs -> 3.21μs (64.9% faster)

def test_sorter_special_characters():
    # Test sorting a list with special characters
    arr = ["!", "@", "#", "$", "%", "^", "&", "*", "A", "a"]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 7.21μs -> 3.58μs (101% faster)

def test_sorter_already_sorted_large():
    # Test sorting a large already sorted list
    arr = list(range(1000))
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 18.4ms -> 30.2μs (61048% faster)

def test_sorter_reverse_sorted_large():
    # Test sorting a large reverse-sorted list
    arr = list(range(999, -1, -1))
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 30.6ms -> 30.1μs (101749% faster)

def test_sorter_mutates_input():
    # Test that the input list is mutated (since the implementation is in-place)
    arr = [3, 2, 1]
    sorter(arr)

def test_sorter_nan_and_inf():
    # Test sorting a list with float('inf'), float('-inf'), and float('nan')
    arr = [float('nan'), 1, float('inf'), -1, float('-inf'), 0]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 6.75μs -> 3.79μs (78.0% faster)
    # NaN is always considered not equal to anything, so it should end up at the end
    expected = [float('-inf'), -1, 0, 1, float('inf'), float('nan')]

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

# ------------------------
# 3. Large Scale Test Cases
# ------------------------

def test_sorter_large_random_integers():
    # Test sorting a large list of random integers
    arr = random.sample(range(-10000, -9000), 1000)  # 1000 unique random ints
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 28.5ms -> 59.2μs (47926% faster)

def test_sorter_large_random_floats():
    # Test sorting a large list of random floats
    arr = [random.uniform(-1e6, 1e6) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 26.7ms -> 290μs (9099% faster)

def test_sorter_large_random_strings():
    # Test sorting a large list of random strings
    arr = [
        ''.join(random.choices(string.ascii_letters + string.digits, k=8))
        for _ in range(1000)
    ]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 29.9ms -> 97.8μs (30429% faster)

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 # 24.8ms -> 49.4μs (50181% faster)

def test_sorter_large_already_sorted_with_duplicates():
    # Test sorting a large already sorted list with duplicates
    arr = sorted([random.choice([1, 2, 3, 4, 5]) for _ in range(1000)])
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 18.4ms -> 26.9μs (68303% faster)

def test_sorter_large_negative_numbers():
    # Test sorting a large list of negative numbers
    arr = [random.randint(-10000, -1) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 27.6ms -> 61.5μs (44755% faster)
# 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 scale random lists
import sys  # used for maxsize in edge cases

# 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 that sorting an empty list returns an empty list
    arr = []
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.50μs -> 2.96μs (52.1% faster)

def test_sorter_single_element():
    # Test that sorting a single-element list returns the same list
    arr = [42]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.12μs -> 3.08μs (33.8% faster)

def test_sorter_sorted_list():
    # Test that a list already sorted remains unchanged
    arr = [1, 2, 3, 4, 5]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.75μs -> 3.00μs (58.3% faster)

def test_sorter_reverse_sorted_list():
    # Test that a reverse-sorted list is sorted correctly
    arr = [5, 4, 3, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 5.08μs -> 2.92μs (74.3% faster)

def test_sorter_unsorted_list():
    # Test that a randomly unsorted list is sorted correctly
    arr = [3, 1, 4, 5, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.50μs -> 3.04μs (47.9% faster)

def test_sorter_with_duplicates():
    # Test that a list with duplicate elements is sorted correctly
    arr = [4, 2, 2, 5, 3, 3, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 5.46μs -> 3.12μs (74.7% faster)

def test_sorter_negative_numbers():
    # Test that a list with negative numbers is sorted correctly
    arr = [-3, -1, -2, 0, 2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.67μs -> 3.17μs (47.4% faster)

def test_sorter_all_equal_elements():
    # Test that a list with all equal elements remains unchanged
    arr = [7, 7, 7, 7]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 3.88μs -> 2.96μs (31.0% faster)

def test_sorter_mixed_integers():
    # Test that a list with positive, negative, and zero is sorted
    arr = [0, -5, 3, -1, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.33μs -> 3.08μs (40.5% faster)

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

def test_sorter_large_and_small_integers():
    # Test with very large and very small integers
    arr = [sys.maxsize, -sys.maxsize - 1, 0, 999999999, -999999999]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 5.92μs -> 3.33μs (77.4% faster)

def test_sorter_already_sorted_with_duplicates():
    # Test with a sorted list containing duplicates
    arr = [1, 2, 2, 3, 4, 4, 5]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.58μs -> 3.12μs (46.7% faster)

def test_sorter_all_negative_duplicates():
    # Test with all negative numbers, some duplicates
    arr = [-2, -3, -2, -1, -3]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.88μs -> 3.04μs (60.3% faster)

def test_sorter_two_elements_sorted():
    # Test with two elements already sorted
    arr = [1, 2]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 3.88μs -> 2.96μs (31.0% faster)

def test_sorter_two_elements_unsorted():
    # Test with two elements in reverse order
    arr = [2, 1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.00μs -> 2.83μs (41.2% faster)

def test_sorter_floats_and_integers():
    # Test with a mix of floats and integers
    arr = [3.2, 1, 2.5, 2, 1.1]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 7.17μs -> 3.58μs (100.0% faster)

def test_sorter_with_zeroes():
    # Test with multiple zeroes in the list
    arr = [0, 0, 1, -1, 0]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 5.17μs -> 3.04μs (69.9% faster)

def test_sorter_minimal_variation():
    # Test with a list where all but one element are the same
    arr = [5, 5, 5, 3, 5]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.38μs -> 3.04μs (43.9% faster)

def test_sorter_long_sorted_prefix():
    # Test with a list that is sorted except for the last element
    arr = [1, 2, 3, 4, 0]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.88μs -> 3.04μs (60.3% faster)

def test_sorter_long_sorted_suffix():
    # Test with a list that is sorted except for the first element
    arr = [5, 1, 2, 3, 4]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.62μs -> 3.00μs (54.2% faster)

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

def test_sorter_large_random_list():
    # Test with a large random list (size 1000)
    arr = random.sample(range(-10000, -9000), 1000)
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 28.1ms -> 61.0μs (45962% faster)

def test_sorter_large_sorted_list():
    # Test with a large already sorted list (size 1000)
    arr = list(range(1000))
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 18.6ms -> 29.2μs (63788% faster)

def test_sorter_large_reverse_sorted_list():
    # Test with a large reverse sorted list (size 1000)
    arr = list(range(999, -1, -1))
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 30.8ms -> 29.0μs (106063% faster)

def test_sorter_large_all_same_elements():
    # Test with a large list where all elements are the same
    arr = [42] * 1000
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 18.3ms -> 27.8μs (65884% faster)

def test_sorter_large_many_duplicates():
    # Test with 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 # 24.9ms -> 48.5μs (51307% faster)

def test_sorter_large_alternating_pattern():
    # Test with a large list of alternating values
    arr = [i % 2 for i in range(1000)]
    expected = sorted(arr)
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 21.7ms -> 43.8μs (49436% faster)

# ------------------------
# Mutation Testing Guards
# ------------------------

def test_sorter_mutation_guard_not_inplace():
    # Ensure that the function can handle a copy and does not mutate the input list outside
    arr = [3, 2, 1]
    arr_copy = arr.copy()
    codeflash_output = sorter(arr_copy); result = codeflash_output # 4.96μs -> 3.21μs (54.6% faster)

def test_sorter_mutation_guard_return_value():
    # Ensure that the function returns the sorted list, not just sorts in-place
    arr = [8, 7, 6]
    codeflash_output = sorter(arr.copy()); result = codeflash_output # 4.38μs -> 2.96μs (47.9% faster)
# 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-mc2jicjp and push.

Codeflash

Here is an optimized version of your program.  
Your original code uses a naïve bubble sort, which is highly inefficient (O(n²)).  
Python has a highly optimized built-in sort, Timsort, running in O(n log n).  
Replacing the manual sort with `list.sort()` (in-place sort) maintains functionality and gives a huge performance boost.



**All function signatures and return results are preserved, as are your print statements.**
This change preserves the intended output and greatly improves speed, especially for large lists.
@codeflash-ai codeflash-ai bot added the ⚡️ codeflash Optimization PR opened by Codeflash AI label Jun 18, 2025
@codeflash-ai codeflash-ai bot requested a review from aseembits93 June 18, 2025 22:45
@codeflash-ai codeflash-ai bot closed this Jun 18, 2025
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codeflash-ai bot commented Jun 18, 2025

This PR has been automatically closed because the original PR #321 by misrasaurabh1 was closed.

@codeflash-ai codeflash-ai bot deleted the codeflash/optimize-sorter-mc2jicjp branch June 18, 2025 22:51
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