From 476ca6eac4511ae62c6a303885f9b0f68260e478 Mon Sep 17 00:00:00 2001
From: labrocadabro <labrocadabro@users.noreply.github.com>
Date: Tue, 22 Apr 2025 11:18:11 -0300
Subject: [PATCH 1/4] Add string reversal function implementation

---
 src/string_reversal.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 src/string_reversal.py

diff --git a/src/string_reversal.py b/src/string_reversal.py
new file mode 100644
index 00000000..84013f1d
--- /dev/null
+++ b/src/string_reversal.py
@@ -0,0 +1,19 @@
+def reverse_string(s: str) -> str:
+    """
+    Reverse a given string.
+
+    Args:
+        s (str): The input string to be reversed.
+
+    Returns:
+        str: The reversed string.
+
+    Raises:
+        TypeError: If the input is not a string.
+    """
+    # Check if input is a string
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string")
+    
+    # Return the reversed string
+    return s[::-1]
\ No newline at end of file

From bcf69ce425c6822a25c6def06d9680784016cf03 Mon Sep 17 00:00:00 2001
From: labrocadabro <labrocadabro@users.noreply.github.com>
Date: Tue, 22 Apr 2025 11:18:23 -0300
Subject: [PATCH 2/4] Add comprehensive tests for string reversal function

---
 tests/test_string_reversal.py | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 tests/test_string_reversal.py

diff --git a/tests/test_string_reversal.py b/tests/test_string_reversal.py
new file mode 100644
index 00000000..60273622
--- /dev/null
+++ b/tests/test_string_reversal.py
@@ -0,0 +1,34 @@
+import pytest
+from src.string_reversal import reverse_string
+
+def test_reverse_string_basic():
+    """Test basic string reversal."""
+    assert reverse_string("hello") == "olleh"
+    assert reverse_string("python") == "nohtyp"
+
+def test_reverse_string_empty():
+    """Test reversing an empty string."""
+    assert reverse_string("") == ""
+
+def test_reverse_string_single_char():
+    """Test reversing a single character."""
+    assert reverse_string("a") == "a"
+
+def test_reverse_string_with_spaces():
+    """Test reversing a string with spaces."""
+    assert reverse_string("hello world") == "dlrow olleh"
+
+def test_reverse_string_with_special_chars():
+    """Test reversing a string with special characters."""
+    assert reverse_string("a1b2c3!@#") == "#@!3c2b1a"
+
+def test_reverse_string_invalid_input():
+    """Test that TypeError is raised for non-string inputs."""
+    with pytest.raises(TypeError, match="Input must be a string"):
+        reverse_string(123)
+    
+    with pytest.raises(TypeError, match="Input must be a string"):
+        reverse_string(None)
+    
+    with pytest.raises(TypeError, match="Input must be a string"):
+        reverse_string(["hello"])
\ No newline at end of file

From 63f45efe334611d8cddc972f10ccf7d309ce2ee1 Mon Sep 17 00:00:00 2001
From: labrocadabro <labrocadabro@users.noreply.github.com>
Date: Tue, 22 Apr 2025 11:19:16 -0300
Subject: [PATCH 3/4] Reimplement string reversal function with two-pointer
 technique

---
 src/string_reversal.py | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/string_reversal.py b/src/string_reversal.py
index 84013f1d..dd84f33f 100644
--- a/src/string_reversal.py
+++ b/src/string_reversal.py
@@ -1,6 +1,6 @@
 def reverse_string(s: str) -> str:
     """
-    Reverse a given string.
+    Reverse a given string character by character.
 
     Args:
         s (str): The input string to be reversed.
@@ -11,9 +11,21 @@ def reverse_string(s: str) -> str:
     Raises:
         TypeError: If the input is not a string.
     """
-    # Check if input is a string
+    # Validate input is a string
     if not isinstance(s, str):
         raise TypeError("Input must be a string")
     
-    # Return the reversed string
-    return s[::-1]
\ No newline at end of file
+    # Convert string to list of characters for manipulation
+    chars = list(s)
+    
+    # Reverse the list in-place using two-pointer technique
+    left, right = 0, len(chars) - 1
+    while left < right:
+        # Swap characters
+        chars[left], chars[right] = chars[right], chars[left]
+        # Move pointers
+        left += 1
+        right -= 1
+    
+    # Convert back to string and return
+    return ''.join(chars)
\ No newline at end of file

From 5f9c3444a6531a6a8c2eec67b436e583a2d2c494 Mon Sep 17 00:00:00 2001
From: labrocadabro <labrocadabro@users.noreply.github.com>
Date: Tue, 22 Apr 2025 11:19:26 -0300
Subject: [PATCH 4/4] Update tests for string reversal function

---
 tests/test_string_reversal.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tests/test_string_reversal.py b/tests/test_string_reversal.py
index 60273622..e4166537 100644
--- a/tests/test_string_reversal.py
+++ b/tests/test_string_reversal.py
@@ -22,6 +22,10 @@ def test_reverse_string_with_special_chars():
     """Test reversing a string with special characters."""
     assert reverse_string("a1b2c3!@#") == "#@!3c2b1a"
 
+def test_reverse_string_mixed_characters():
+    """Test reversing a string with mixed character types."""
+    assert reverse_string("Hello, World! 123") == "321 !dlroW ,olleH"
+
 def test_reverse_string_invalid_input():
     """Test that TypeError is raised for non-string inputs."""
     with pytest.raises(TypeError, match="Input must be a string"):