⚡️ Speed up function mysorter by 20,147%

[codeflash-ai]

📄 20,147% (201.47x) speedup for mysorter in codeflash/bubble_sort.py

⏱️ Runtime : 406 milliseconds → 2.01 milliseconds (best of 133 runs)

📝 Explanation and details

The optimized code replaces a manual bubble sort implementation with Python's built-in arr.sort() method, delivering a 201x speedup.

Key optimization:

• Algorithm change: Replaced O(n²) bubble sort with Python's Timsort algorithm (O(n log n) average case)
• Implementation efficiency: Python's built-in sort is implemented in highly optimized C code

Why this is dramatically faster:
The original bubble sort performs ~14 million operations for moderate-sized lists (as shown in the profiler), with nested loops comparing and swapping elements repeatedly. Python's Timsort is:

1. Algorithmically superior: O(n log n) vs O(n²) complexity
2. Implementation optimized: C-level implementation vs Python bytecode
3. Adaptive: Performs even better on partially sorted data

Test case performance:

• Small lists (empty, single element): Minimal difference, both are fast
• Large lists (1000+ elements): Massive improvements, especially for reverse-sorted data which is bubble sort's worst case
• All data types: Works efficiently with integers, floats, strings, and complex objects
• Edge cases: Handles NaN, infinity, and mixed numeric types correctly

The optimization maintains identical behavior (in-place sorting, same return value) while dramatically improving performance for any list with more than a few elements.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 62 Passed
⏪ Replay Tests	✅ 1 Passed
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

import random  # used for generating large random lists
import string  # used for string sorting tests
import sys  # used for testing with large/small integers

# imports
import pytest  # used for our unit tests
from codeflash.bubble_sort import mysorter

# unit tests

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

def test_empty_list():
    # Test sorting an empty list
    arr = []
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_single_element():
    # Test sorting a list with one element
    arr = [42]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

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

def test_reverse_sorted_integers():
    # Test sorting a reverse sorted list
    arr = [5, 4, 3, 2, 1]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_unsorted_integers():
    # Test sorting a randomly ordered list
    arr = [3, 1, 4, 5, 2]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_duplicates():
    # Test sorting a list with duplicate values
    arr = [4, 2, 2, 1, 3, 4]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

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

def test_floats_and_integers():
    # Test sorting a list with both floats and integers
    arr = [3.1, 2, 5.5, 1, 3]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

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

def test_mixed_case_strings():
    # Test sorting a list of mixed-case strings
    arr = ["Banana", "apple", "Cherry"]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

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

def test_all_equal_elements():
    # Test sorting a list where all elements are equal
    arr = [7, 7, 7, 7]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_two_elements_sorted():
    # Test sorting a two-element list that is already sorted
    arr = [1, 2]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_two_elements_unsorted():
    # Test sorting a two-element list that is not sorted
    arr = [2, 1]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_large_positive_and_negative():
    # Test sorting with very large and very small integers
    arr = [sys.maxsize, -sys.maxsize-1, 0, 999, -1000]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_strings_with_empty_string():
    # Test sorting strings with empty string included
    arr = ["zebra", "", "apple"]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_strings_with_spaces():
    # Test sorting strings with leading/trailing spaces
    arr = [" apple", "apple", "  apple", "banana"]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_list_with_none_raises():
    # Test that sorting a list with None raises TypeError
    arr = [1, None, 2]
    with pytest.raises(TypeError):
        mysorter(arr.copy())

def test_list_with_incomparable_types_raises():
    # Test that sorting a list with incomparable types raises TypeError
    arr = [1, "a", 2]
    with pytest.raises(TypeError):
        mysorter(arr.copy())

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

def test_list_with_inf():
    # Test sorting a list with float('inf') and float('-inf')
    arr = [1, float('inf'), 2, float('-inf')]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

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

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

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

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

def test_large_list_with_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 = mysorter(arr.copy()); result = codeflash_output

def test_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 = mysorter(arr.copy()); result = codeflash_output

def test_large_list_with_negative_and_positive_floats():
    # Test sorting a large list with negative and positive floats
    arr = [random.uniform(-1000, 1000) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = mysorter(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.
#------------------------------------------------
import random  # used for generating large random test cases
import string  # used for string sorting test cases
import sys  # used for edge integer values

# imports
import pytest  # used for our unit tests
from codeflash.bubble_sort import mysorter

# unit tests

# --- Basic Test Cases ---

def test_empty_list():
    # Sorting an empty list should return an empty list
    codeflash_output = mysorter([])

def test_single_element():
    # Sorting a list with a single element should return the same list
    codeflash_output = mysorter([42])

def test_already_sorted():
    # Sorting an already sorted list should not change it
    codeflash_output = mysorter([1, 2, 3, 4, 5])

def test_reverse_sorted():
    # Sorting a reverse-sorted list should return a sorted list
    codeflash_output = mysorter([5, 4, 3, 2, 1])

def test_unsorted_integers():
    # Sorting a list with unsorted integers
    codeflash_output = mysorter([3, 1, 4, 1, 5, 9, 2])

def test_duplicates():
    # Sorting a list with duplicate elements
    codeflash_output = mysorter([2, 3, 2, 1, 3])

def test_negative_numbers():
    # Sorting a list with negative numbers
    codeflash_output = mysorter([-3, -1, -2, 0, 2, 1])

def test_mixed_positive_negative():
    # Sorting a list with both positive and negative numbers
    codeflash_output = mysorter([0, -1, 3, -2, 2, 1])

def test_all_equal():
    # Sorting a list where all elements are equal
    codeflash_output = mysorter([7, 7, 7, 7])

def test_floats():
    # Sorting a list with floating-point numbers
    codeflash_output = mysorter([3.1, 2.7, 4.5, 1.0])

def test_mixed_int_float():
    # Sorting a list with both integers and floats
    codeflash_output = mysorter([1, 2.2, 0, 3.3, 2])

def test_strings():
    # Sorting a list of strings should sort lexicographically
    codeflash_output = mysorter(["banana", "apple", "cherry"])

def test_single_char_strings():
    # Sorting single-character strings
    codeflash_output = mysorter(['c', 'a', 'b'])

# --- Edge Test Cases ---

def test_large_integers():
    # Sorting a list with very large integers
    arr = [sys.maxsize, -sys.maxsize-1, 0, 1, -1]
    codeflash_output = mysorter(arr)

def test_min_max_float():
    # Sorting a list with min and max float values
    arr = [float('inf'), float('-inf'), 0.0, 1.0, -1.0]
    codeflash_output = mysorter(arr)

def test_nan_in_list():
    # Sorting a list with NaN values: NaNs should end up at the end (Python's default)
    arr = [3, float('nan'), 2, 1]
    codeflash_output = mysorter(arr.copy()); result = codeflash_output

def test_empty_string():
    # Sorting a list with empty strings
    arr = ["", "a", "b", ""]
    codeflash_output = mysorter(arr)

def test_unicode_strings():
    # Sorting a list with unicode characters
    arr = ["éclair", "apple", "Éclair", "banana"]
    # Python sorts uppercase before lowercase, and accents after
    codeflash_output = mysorter(arr)

def test_boolean_values():
    # Sorting a list with boolean values (False < True)
    arr = [True, False, True, False]
    codeflash_output = mysorter(arr)

def test_tuple_elements():
    # Sorting a list of tuples (lexicographic order)
    arr = [(2, 3), (1, 2), (2, 2), (1, 1)]
    codeflash_output = mysorter(arr)

def test_custom_objects_raises():
    # Sorting a list of custom objects should raise TypeError if not comparable
    class A:
        pass
    arr = [A(), A()]
    with pytest.raises(TypeError):
        mysorter(arr)

def test_mixed_types_raises():
    # Sorting a list with mixed types (e.g., int and str) should raise TypeError
    arr = [1, "a", 2]
    with pytest.raises(TypeError):
        mysorter(arr)

def test_none_in_list_raises():
    # Sorting a list with None and numbers should raise TypeError
    arr = [None, 1, 2]
    with pytest.raises(TypeError):
        mysorter(arr)

def test_list_of_lists():
    # Sorting a list of lists lexicographically
    arr = [[2, 3], [1], [2, 2], [1, 1]]
    codeflash_output = mysorter(arr)

def test_list_with_empty_lists():
    # Sorting a list with empty lists and non-empty lists
    arr = [[], [1], [], [0]]
    codeflash_output = mysorter(arr)

# --- Large Scale Test Cases ---

def test_large_sorted_list():
    # Sorting a large already sorted list (performance and correctness)
    arr = list(range(1000))
    codeflash_output = mysorter(arr.copy())

def test_large_reverse_sorted_list():
    # Sorting a large reverse-sorted list (worst-case for bubble sort)
    arr = list(range(999, -1, -1))
    codeflash_output = mysorter(arr.copy())

def test_large_random_list():
    # Sorting a large random list of integers
    arr = random.sample(range(-10000, -9000), 1000)
    expected = sorted(arr)
    codeflash_output = mysorter(arr.copy())

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

def test_large_string_list():
    # 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 = mysorter(arr.copy())

def test_large_float_list():
    # Sorting a large list of random floats
    arr = [random.uniform(-1e6, 1e6) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = mysorter(arr.copy())

def test_large_boolean_list():
    # Sorting a large list of boolean values
    arr = [random.choice([True, False]) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = mysorter(arr.copy())

def test_large_list_of_lists():
    # Sorting a large list of lists of integers
    arr = [random.sample(range(10), random.randint(0, 5)) for _ in range(1000)]
    expected = sorted(arr)
    codeflash_output = mysorter(arr.copy())

# --- Mutability Test ---

def test_mutability_of_input():
    # The function should sort in-place and return the same object
    arr = [3, 2, 1]
    codeflash_output = mysorter(arr); result = codeflash_output

# --- Determinism Test ---

def test_determinism():
    # Sorting the same list twice should give the same result
    arr = [random.randint(-100, 100) for _ in range(100)]
    codeflash_output = mysorter(arr.copy()); result1 = codeflash_output
    codeflash_output = mysorter(arr.copy()); result2 = codeflash_output
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.

⏪ Replay Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup

To edit these changes git checkout codeflash/optimize-mysorter-me365hxy and push.