From d49a112a1c31824d121507e04649c734a5ca642d Mon Sep 17 00:00:00 2001
From: Orji Patricia <81320550+otrisha@users.noreply.github.com>
Date: Sat, 12 Sep 2026 02:06:21 +0100
Subject: [PATCH 1/5] sorts: make comb sort generic for comparable items

---
 sorts/comb_sort.py | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/sorts/comb_sort.py b/sorts/comb_sort.py
index 72caeb9c7350..cfa6539aefac 100644
--- a/sorts/comb_sort.py
+++ b/sorts/comb_sort.py
@@ -18,8 +18,14 @@
 python comb_sort.py
 """
 
+from typing import Any, Protocol
 
-def comb_sort(data: list) -> list:
+
+class Comparable(Protocol):
+    def __lt__(self, other: Any, /) -> bool: ...
+
+
+def comb_sort[T: Comparable](data: list[T]) -> list[T]:
     """Pure implementation of comb sort algorithm in Python
     :param data: mutable collection with comparable items
     :return: the same collection in ascending order
@@ -32,6 +38,14 @@ def comb_sort(data: list) -> list:
     [-15, -7, 0, 2, 3, 8, 45, 99]
     >>> comb_sort([2, 0, 3, 4, 5, 6, 1])
     [0, 1, 2, 3, 4, 5, 6]
+    >>> comb_sort(["c", "a", "b"])
+    ['a', 'b', 'c']
+    >>> comb_sort([2.5, -1.0, 0.0])
+    [-1.0, 0.0, 2.5]
+    >>> comb_sort([1, "a"])
+    Traceback (most recent call last):
+    ...
+    TypeError: '<' not supported between instances of 'str' and 'int'
     """
     shrink_factor = 1.3
     gap = len(data)
@@ -47,7 +61,7 @@ def comb_sort(data: list) -> list:
 
         index = 0
         while index + gap < len(data):
-            if data[index] > data[index + gap]:
+            if data[index + gap] < data[index]:
                 # Swap values
                 data[index], data[index + gap] = data[index + gap], data[index]
                 completed = False

From 8b9fbab0400d9789095a31b6ed65ecf035202709 Mon Sep 17 00:00:00 2001
From: Orji Patricia <81320550+otrisha@users.noreply.github.com>
Date: Sat, 12 Sep 2026 02:06:34 +0100
Subject: [PATCH 2/5] tests: cover comb sort incomparable inputs

---
 tests/test_sorts.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/test_sorts.py b/tests/test_sorts.py
index 799ab5979dff..adabc2c7d43a 100644
--- a/tests/test_sorts.py
+++ b/tests/test_sorts.py
@@ -116,6 +116,7 @@ def test_sort_matches_builtin(sort, case):
         bubble_sort_recursive,
         circle_sort,
         cocktail_shaker_sort,
+        comb_sort,
         gnome_sort,
         insertion_sort,
         merge_sort,

From fff2fb7b3e99b07a99cf00af6f072ec3b5dc48f3 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Sat, 12 Sep 2026 07:45:23 +0200
Subject: [PATCH 3/5] Update sorts/comb_sort.py

---
 sorts/comb_sort.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sorts/comb_sort.py b/sorts/comb_sort.py
index cfa6539aefac..1d7c90de87ea 100644
--- a/sorts/comb_sort.py
+++ b/sorts/comb_sort.py
@@ -40,7 +40,9 @@ def comb_sort[T: Comparable](data: list[T]) -> list[T]:
     [0, 1, 2, 3, 4, 5, 6]
     >>> comb_sort(["c", "a", "b"])
     ['a', 'b', 'c']
-    >>> comb_sort([2.5, -1.0, 0.0])
+    >>> comb_sort("cab")
+    ['a', 'b', 'c']
+    >>> comb_sort([2.5, -1, 0.0])
     [-1.0, 0.0, 2.5]
     >>> comb_sort([1, "a"])
     Traceback (most recent call last):

From a5c73c814b5b3ff1d3a40059a6bbda283c1b7a82 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Sat, 12 Sep 2026 07:49:12 +0200
Subject: [PATCH 4/5] Apply suggestion from @cclauss

---
 sorts/comb_sort.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/sorts/comb_sort.py b/sorts/comb_sort.py
index 1d7c90de87ea..179d1e74bbed 100644
--- a/sorts/comb_sort.py
+++ b/sorts/comb_sort.py
@@ -40,8 +40,6 @@ def comb_sort[T: Comparable](data: list[T]) -> list[T]:
     [0, 1, 2, 3, 4, 5, 6]
     >>> comb_sort(["c", "a", "b"])
     ['a', 'b', 'c']
-    >>> comb_sort("cab")
-    ['a', 'b', 'c']
     >>> comb_sort([2.5, -1, 0.0])
     [-1.0, 0.0, 2.5]
     >>> comb_sort([1, "a"])

From b43b35835665093a775ff204d5accab751bcf762 Mon Sep 17 00:00:00 2001
From: Christian Clauss <cclauss@me.com>
Date: Sat, 12 Sep 2026 07:51:44 +0200
Subject: [PATCH 5/5] Apply suggestion from @cclauss

---
 sorts/comb_sort.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sorts/comb_sort.py b/sorts/comb_sort.py
index 179d1e74bbed..46f6c77c5be7 100644
--- a/sorts/comb_sort.py
+++ b/sorts/comb_sort.py
@@ -41,7 +41,7 @@ def comb_sort[T: Comparable](data: list[T]) -> list[T]:
     >>> comb_sort(["c", "a", "b"])
     ['a', 'b', 'c']
     >>> comb_sort([2.5, -1, 0.0])
-    [-1.0, 0.0, 2.5]
+    [-1, 0.0, 2.5]
     >>> comb_sort([1, "a"])
     Traceback (most recent call last):
     ...