From a5ef73b40259a2a504bc00bd4a7ac383cb390ed8 Mon Sep 17 00:00:00 2001
From: Hyun Chan Park <126567839+Chanz82@users.noreply.github.com>
Date: Tue, 4 Aug 2026 23:54:09 +0100
Subject: [PATCH 1/2] Add reverse linked list solution

---
 reverse-linked-list/Chanz82.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 reverse-linked-list/Chanz82.py

diff --git a/reverse-linked-list/Chanz82.py b/reverse-linked-list/Chanz82.py
new file mode 100644
index 0000000000..e4fc938828
--- /dev/null
+++ b/reverse-linked-list/Chanz82.py
@@ -0,0 +1,19 @@
+# Definition for singly-linked list.
+# class ListNode:
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+class Solution:
+    def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
+        dummy = ListNode()
+        dummy = head
+        prev = None
+
+        while dummy:
+            nextNode = dummy.next
+            dummy.next = prev
+            prev = dummy
+            dummy = nextNode
+
+        return prev
+

From 1fe9877ab06e55269877b2b0fde9713563dc474b Mon Sep 17 00:00:00 2001
From: Hyun Chan Park <126567839+Chanz82@users.noreply.github.com>
Date: Fri, 7 Aug 2026 19:22:27 +0100
Subject: [PATCH 2/2] Add lengthOfLongestSubstring method in Solution class

Implement a solution to find the length of the longest substring without repeating characters.
---
 .../Chanz82.py                                     | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 longest-substring-without-repeating-characters/Chanz82.py

diff --git a/longest-substring-without-repeating-characters/Chanz82.py b/longest-substring-without-repeating-characters/Chanz82.py
new file mode 100644
index 0000000000..9ab9ae5cff
--- /dev/null
+++ b/longest-substring-without-repeating-characters/Chanz82.py
@@ -0,0 +1,14 @@
+class Solution:
+    def lengthOfLongestSubstring(self, s: str) -> int:
+        left = 0
+        max_len = 0
+        visited = {}
+
+        for right, ch in enumerate(s):
+            if ch in visited and visited[ch] >= left: 
+                left = visited[ch] + 1 # 현재 윈도우 상에서 중복 문자가 발견되었기 때문에 윈도우를 중복 문자 이후로 옮김.
+            
+            visited[ch] = right
+            max_len = max(max_len, right - left + 1)
+
+        return max_len