From f990d1bd32514d74148ce5113f22f7adfc9fd1ab Mon Sep 17 00:00:00 2001
From: unknown <shineyrbl@gmail.com>
Date: Sat, 11 Apr 2026 18:35:10 +0530
Subject: [PATCH 1/4] Add input validation to reverse_letters function

---
 strings/reverse_letters.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/strings/reverse_letters.py b/strings/reverse_letters.py
index cd1b7832d066..f3b5e7dadbb0 100644
--- a/strings/reverse_letters.py
+++ b/strings/reverse_letters.py
@@ -12,6 +12,12 @@ def reverse_letters(sentence: str, length: int = 0) -> str:
     >>> reverse_letters("racecar")
     'racecar'
     """
+    if not isinstance(sentence, str):
+        raise TypeError("sentence must be a string")
+
+    if not isinstance(length, int) or length < 0:
+        raise ValueError("length must be a non-negative integer")
+    
     return " ".join(
         word[::-1] if len(word) > length else word for word in sentence.split()
     )

From 5d93c442a7fb56e83767dfad1b2abfc998ef7ed1 Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sat, 11 Apr 2026 13:07:55 +0000
Subject: [PATCH 2/4] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 strings/reverse_letters.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/strings/reverse_letters.py b/strings/reverse_letters.py
index f3b5e7dadbb0..770796f8110e 100644
--- a/strings/reverse_letters.py
+++ b/strings/reverse_letters.py
@@ -17,7 +17,7 @@ def reverse_letters(sentence: str, length: int = 0) -> str:
 
     if not isinstance(length, int) or length < 0:
         raise ValueError("length must be a non-negative integer")
-    
+
     return " ".join(
         word[::-1] if len(word) > length else word for word in sentence.split()
     )

From f6e7db6e33da05fd33e36776660ac11d6184056a Mon Sep 17 00:00:00 2001
From: unknown <shineyrbl@gmail.com>
Date: Sun, 12 Apr 2026 14:48:10 +0530
Subject: [PATCH 3/4] Add input validation to palindrome functions

---
 strings/palindrome.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/strings/palindrome.py b/strings/palindrome.py
index 4df5639b0c49..83fcdafc123a 100644
--- a/strings/palindrome.py
+++ b/strings/palindrome.py
@@ -24,8 +24,15 @@ def is_palindrome(s: str) -> bool:
 
     >>> all(is_palindrome(key) == value for key, value in test_data.items())
     True
+    >>> is_palindrome(123)
+    Traceback (most recent call last):
+        ...
+    TypeError: Input must be a string
     """
 
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string")
+
     start_i = 0
     end_i = len(s) - 1
     while start_i < end_i:
@@ -44,6 +51,9 @@ def is_palindrome_traversal(s: str) -> bool:
     >>> all(is_palindrome_traversal(key) == value for key, value in test_data.items())
     True
     """
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string")
+    
     end = len(s) // 2
     n = len(s)
 
@@ -63,6 +73,9 @@ def is_palindrome_recursive(s: str) -> bool:
     >>> all(is_palindrome_recursive(key) == value for key, value in test_data.items())
     True
     """
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string")
+    
     if len(s) <= 1:
         return True
     if s[0] == s[len(s) - 1]:
@@ -78,6 +91,9 @@ def is_palindrome_slice(s: str) -> bool:
     >>> all(is_palindrome_slice(key) == value for key, value in test_data.items())
     True
     """
+    if not isinstance(s, str):
+        raise TypeError("Input must be a string")
+
     return s == s[::-1]
 
 

From 49f57d298fb14fc673407f15ee4fb7c96ccb714e Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Sun, 12 Apr 2026 09:20:55 +0000
Subject: [PATCH 4/4] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 strings/palindrome.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/strings/palindrome.py b/strings/palindrome.py
index 83fcdafc123a..7a513942c43d 100644
--- a/strings/palindrome.py
+++ b/strings/palindrome.py
@@ -53,7 +53,7 @@ def is_palindrome_traversal(s: str) -> bool:
     """
     if not isinstance(s, str):
         raise TypeError("Input must be a string")
-    
+
     end = len(s) // 2
     n = len(s)
 
@@ -75,7 +75,7 @@ def is_palindrome_recursive(s: str) -> bool:
     """
     if not isinstance(s, str):
         raise TypeError("Input must be a string")
-    
+
     if len(s) <= 1:
         return True
     if s[0] == s[len(s) - 1]: