diff --git a/linked-list-cycle/Seoya0512.py b/linked-list-cycle/Seoya0512.py
new file mode 100644
index 0000000000..3cad5460c2
--- /dev/null
+++ b/linked-list-cycle/Seoya0512.py
@@ -0,0 +1,9 @@
+class Solution:
+    def hasCycle(self, head: Optional[ListNode]) -> bool:
+        cycle_set = set()
+        while head:
+            if head in cycle_set:
+                return True
+            cycle_set.add(head)
+            head = head.next
+        return False
diff --git a/maximum-product-subarray/Seoya0512.py b/maximum-product-subarray/Seoya0512.py
new file mode 100644
index 0000000000..c26f4ea59e
--- /dev/null
+++ b/maximum-product-subarray/Seoya0512.py
@@ -0,0 +1,19 @@
+'''
+이전 곱을 저장해서 곱셈 연산을 줄이는 방식
+해당 연산 방식은 Time Limited Exceeded 오류를 발생했습니다. 
+
+시간 복잡도: O(n^2)
+- 외부 for-loop과 내부 for-loop이 각각 n번씩 실행되기 때문
+공간 복잡도: O(1)
+'''
+class Solution:
+    def maxProduct(self, nums: List[int]) -> int:
+        max_product = nums[0]
+
+        for i in range(len(nums)):
+            prev = 1
+            for j in range(i, len(nums)):
+                prev = prev * nums[j]
+                max_product = max(max_product, prev)
+
+        return max_product