diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000000..b5b515db3a
Binary files /dev/null and b/.DS_Store differ
diff --git a/sam_lee/Contains_Duplicate.py b/sam_lee/Contains_Duplicate.py
new file mode 100644
index 0000000000..0ac7e3aeed
--- /dev/null
+++ b/sam_lee/Contains_Duplicate.py
@@ -0,0 +1,10 @@
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        my_dict = {}
+
+        for num in nums:
+            if num in my_dict:
+                return True
+            my_dict[num] = 0
+        
+        return False
\ No newline at end of file
diff --git a/sam_lee/Two_Sum b/sam_lee/Two_Sum
new file mode 100644
index 0000000000..d2be88998c
--- /dev/null
+++ b/sam_lee/Two_Sum
@@ -0,0 +1,10 @@
+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+         my_dict = {}
+         
+         for i in range(len(nums)):
+            complement = target - nums[i]
+            if complement in my_dict:
+                return [my_dict[complement], i]
+            
+            my_dict[nums[i]] = i
\ No newline at end of file
diff --git a/sam_lee/Valid_Anagram b/sam_lee/Valid_Anagram
new file mode 100644
index 0000000000..8f4adf175a
--- /dev/null
+++ b/sam_lee/Valid_Anagram
@@ -0,0 +1,18 @@
+# Time Complexity : O(nlog(n))
+# Space Complexity : 0(1)
+class Solution:
+    def isAnagram(self, s: str, t: str) -> bool:
+        return sorted(s) == sorted(t)
+
+class Solution:
+    def isAnagram(self, s: str, t: str) -> bool:
+        my_dict1 = {}
+        my_dict2 = {}
+
+        for char in s:
+            my_dict1[char] = my_dict1.get(char, 0) + 1
+        
+        for char in t:
+            my_dict2[char] = my_dict2.get(char, 0) + 1
+        
+        return my_dict1 == my_dict2
\ No newline at end of file