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
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
+