From e890414c9b4bfd92caad5add935513fb39ad2130 Mon Sep 17 00:00:00 2001
From: dohee <kimdohee@sheridancollege.ca>
Date: Tue, 3 Mar 2026 10:36:37 -0500
Subject: [PATCH 1/3] 217. Contains Duplicate Solution

---
 contains-duplicate/doh6077.py | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/contains-duplicate/doh6077.py b/contains-duplicate/doh6077.py
index bc14e47f24..f755a81036 100644
--- a/contains-duplicate/doh6077.py
+++ b/contains-duplicate/doh6077.py
@@ -1,10 +1,8 @@
+# https://leetcode.com/problems/contains-duplicate/description/
 
-# set에 저장하면서 중복 여부 확인하기
 class Solution:
-    def containsDuplicate(self, nums: list[int]) -> bool:
-        hashset = set()
-        for i in nums:
-            if i in hashset:
-                return True
-            hashset.add(i)
-        return False
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        # Create a set to store unique numbers from nums
+        nums_set = set(nums)
+        return len(nums_set) != len(nums)
+        
\ No newline at end of file

From 03641f93aae037e5a23398cdd76df82bfc54954e Mon Sep 17 00:00:00 2001
From: dohee <kimdohee@sheridancollege.ca>
Date: Tue, 3 Mar 2026 10:43:08 -0500
Subject: [PATCH 2/3] =?UTF-8?q?=EC=A4=84=EB=B0=94=EA=BF=88?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 contains-duplicate/doh6077.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/contains-duplicate/doh6077.py b/contains-duplicate/doh6077.py
index f755a81036..11a03c3ca6 100644
--- a/contains-duplicate/doh6077.py
+++ b/contains-duplicate/doh6077.py
@@ -5,4 +5,3 @@ def containsDuplicate(self, nums: List[int]) -> bool:
         # Create a set to store unique numbers from nums
         nums_set = set(nums)
         return len(nums_set) != len(nums)
-        
\ No newline at end of file

From 7755c5d899e67dab9b29379e90dd86b486ddf2b6 Mon Sep 17 00:00:00 2001
From: dohee <kimdohee@sheridancollege.ca>
Date: Tue, 3 Mar 2026 11:20:36 -0500
Subject: [PATCH 3/3] Two Sum solution

---
 two-sum/doh6077.py | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/two-sum/doh6077.py b/two-sum/doh6077.py
index 2054ef0def..d8c8a3683a 100644
--- a/two-sum/doh6077.py
+++ b/two-sum/doh6077.py
@@ -1,8 +1,24 @@
+# 6기 
+# class Solution:
+#     def twoSum(self, nums: list[int], target: int) -> list[int]:
+#         prevMap = {} # val : index 
+#         for i, n in enumerate(nums):
+#             diff = target - n 
+#             if diff in prevMap:
+#                 return [prevMap[diff], i]
+#             prevMap[n] = i 
+
+# 7기 
+# https://leetcode.com/problems/two-sum/description/
 class Solution:
-    def twoSum(self, nums: list[int], target: int) -> list[int]:
-        prevMap = {} # val : index 
-        for i, n in enumerate(nums):
-            diff = target - n 
-            if diff in prevMap:
-                return [prevMap[diff], i]
-            prevMap[n] = i 
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        # use Hash map to save num and index 
+        nums_hm = {}
+
+        for i, num in enumerate(nums):
+            find_val = target - num
+
+            if find_val in nums_hm:
+                return [nums_hm[find_val], i]
+
+            nums_hm[num] = i