From c15df81f741d236190a3127e6ff203e1bdb65e1d Mon Sep 17 00:00:00 2001
From: sainaga00 <nsaikamsai@gmail.com>
Date: Tue, 3 Feb 2026 15:01:12 -0500
Subject: [PATCH] Add MinStack and HashSet implementations

---
 designHashSet.py | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
 minStack.py      | 33 +++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+)
 create mode 100644 designHashSet.py
 create mode 100644 minStack.py

diff --git a/designHashSet.py b/designHashSet.py
new file mode 100644
index 00000000..9c42388c
--- /dev/null
+++ b/designHashSet.py
@@ -0,0 +1,51 @@
+# Time Complexity: O(1) average
+# Space Complexity: O(n) where n is the number of keys 
+# Did this code successfully run on LeetCode: Yes
+# Any problem faced while coding: No
+# Approach: Used chaining with linked list for collision
+
+
+class Node:
+    def __init__(self,key):
+        self.key = key
+        self.next = None
+
+class MyHashSet:
+    def __init__(self):
+        self.hset = [Node(0) for i in range(10**4)]
+
+    def add(self, key: int) -> None:
+        curr = self.hset[key % len(self.hset)]
+        while curr.next:
+            if curr.next.key == key:
+                return
+            curr = curr.next
+        curr.next = Node(key)
+
+    def remove(self, key: int) -> None:
+        curr = self.hset[key % len(self.hset)]
+        while curr.next:
+            if curr.next.key == key:
+                curr.next = curr.next.next
+                return
+            curr = curr.next
+
+    def contains(self, key: int) -> bool:
+        curr = self.hset[key % len(self.hset)]
+        while curr.next:
+            if curr.next.key == key:
+                return True
+            curr = curr.next
+        return False
+        
+
+
+# Your MyHashSet object will be instantiated and called as such:
+# obj = MyHashSet()
+# obj.add(key)
+# obj.remove(key)
+# param_3 = obj.contains(key)
+
+
+
+
diff --git a/minStack.py b/minStack.py
new file mode 100644
index 00000000..8974a5e5
--- /dev/null
+++ b/minStack.py
@@ -0,0 +1,33 @@
+# Time Complexity : O(1) for all operations
+# Space Complexity : O(n) -> n is no of elements in stack
+# Did this code successfully run on Leetcode : Yes
+# Any problem you faced while coding this : No
+# Approach: Store each value along with the minimum value seen so far at that point.
+
+
+class MinStack:
+    def __init__(self):
+        self.st = []
+
+    def push(self, val: int) -> None:
+        curr_min = self.getMin()
+        if curr_min == None or curr_min > val:
+            curr_min = val
+        self.st.append([val,curr_min])
+
+    def pop(self) -> None:
+        self.st.pop()
+
+    def top(self) -> int:
+        return self.st[-1][0]
+
+    def getMin(self) -> int:
+        return self.st[-1][1] if self.st else None
+
+
+# Your MinStack object will be instantiated and called as such:
+# obj = MinStack()
+# obj.push(val)
+# obj.pop()
+# param_3 = obj.top()
+# param_4 = obj.getMin()
\ No newline at end of file