diff --git a/hashset.py b/hashset.py
new file mode 100644
index 00000000..2bbaf72a
--- /dev/null
+++ b/hashset.py
@@ -0,0 +1,26 @@
+class MyHashSet:
+
+    def __init__(self):
+        self.set = [False] * (10 ** 6 + 1)
+
+    def add(self, key: int) -> None:
+        self.set[key] = True
+
+    def remove(self, key: int) -> None:
+        self.set[key] = False
+
+    def contains(self, key: int) -> bool:
+        return self.set[key]
+
+# Your MyHashSet object will be instantiated and called as such:
+# obj = MyHashSet()
+# obj.add(key)
+# obj.remove(key)
+# param_3 = obj.contains(key)
+
+# Time complexity -
+# add	O(1)
+# remove	O(1)
+# contains	O(1)
+
+# Space Complexity = O(10^6)
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diff --git a/minstack.py b/minstack.py
new file mode 100644
index 00000000..dc7abd23
--- /dev/null
+++ b/minstack.py
@@ -0,0 +1,34 @@
+class MinStack:
+
+    def __init__(self):
+        self.stack = []
+        self.minStack = []
+
+    def push(self, val):
+        self.stack.append(val)
+        if not self.minStack or val <= self.minStack[-1]:
+            self.minStack.append(val)
+
+    def pop(self):
+        if self.stack.pop() == self.minStack[-1]:
+            self.minStack.pop()
+
+    def top(self):
+        return self.stack[-1]
+
+    def getMin(self):
+        return self.minStack[-1]
+
+# Your MinStack object will be instantiated and called as such:
+# obj = MinStack()
+# obj.push(value)
+# obj.pop()
+# param_3 = obj.top()
+# param_4 = obj.getMin()
+
+# Time and Space complexities for minstack
+# Operation	Time	Space
+# push	    O(1)	O(n)
+# pop	    O(1)	O(1)
+# top	    O(1)	O(1)
+# getMin	O(1)	O(1)
\ No newline at end of file