From 8a5b305f797d8176919851c43b067c1d9beea8b6 Mon Sep 17 00:00:00 2001
From: agk-s30 <anikesh.kamath@hotmail.com>
Date: Thu, 30 Jul 2026 01:21:48 -0700
Subject: [PATCH 1/2] Add MinStack class implementation

Implement MinStack class with push, pop, top, and getMin methods.
---
 Exercise_2.py | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Exercise_2.py

diff --git a/Exercise_2.py b/Exercise_2.py
new file mode 100644
index 00000000..d4fa3d55
--- /dev/null
+++ b/Exercise_2.py
@@ -0,0 +1,29 @@
+# Min Stack
+# https://leetcode.com/problems/min-stack/description/
+
+# Time complexity: O(1)
+# Space complexity: O(n)
+
+# Uses an additional stack to maintain the current minimum value. Push to min_stack when change in min value or equal. Similarly, pop when min value is popped.
+
+class MinStack:
+
+    def __init__(self):
+        self.stack = []
+        self.min_stack = []
+
+    def push(self, value: int) -> None:
+        self.stack.append(value)
+        if not self.min_stack or value <= self.min_stack[-1]:
+            self.min_stack.append(value)
+
+    def pop(self) -> None:
+        if self.min_stack[-1] == self.stack[-1]:
+            self.min_stack.pop()
+        self.stack.pop() 
+
+    def top(self) -> int:
+        return self.stack[-1]
+
+    def getMin(self) -> int:
+        return self.min_stack[-1]

From 6152b4123cace935890c665dbbd9b36ed8206dd0 Mon Sep 17 00:00:00 2001
From: agk-s30 <anikesh.kamath@hotmail.com>
Date: Thu, 30 Jul 2026 01:41:48 -0700
Subject: [PATCH 2/2] Add MyHashSet implementation with basic operations

Implement a MyHashSet class with add, remove, and contains methods using double hashing.
---
 Exercise_1.py | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 Exercise_1.py

diff --git a/Exercise_1.py b/Exercise_1.py
new file mode 100644
index 00000000..31313eea
--- /dev/null
+++ b/Exercise_1.py
@@ -0,0 +1,57 @@
+# Design HashSet
+# https://leetcode.com/problems/design-hashset/description/
+
+# Time complexity: O(1)
+# Space complexity: O(n)
+
+# Uses double hashing - primary hash to find which bucket, secondary hash to find position in bucket;
+# also uses boolean values instead of int to save space - works well here because this is a set and the operations only require "check if exisits" operations
+
+class MyHashSet:
+
+    def __init__(self):
+        self.primary_buckets = 1000
+        self.secondary_buckets = 1001
+
+        # Each primary bucket is initialized only when needed.
+        self.storage = [None] * self.primary_buckets
+
+    def _primary_hash(self, key: int) -> int:
+        return key % self.primary_buckets
+
+    def _secondary_hash(self, key: int) -> int:
+        return key // self.primary_buckets
+
+    def add(self, key: int) -> None:
+        primary_index = self._primary_hash(key)
+        secondary_index = self._secondary_hash(key)
+
+        if self.storage[primary_index] is None:
+            self.storage[primary_index] = [False] * self.secondary_buckets
+
+        self.storage[primary_index][secondary_index] = True
+
+    def remove(self, key: int) -> None:
+        primary_index = self._primary_hash(key)
+
+        if self.storage[primary_index] is None:
+            return
+
+        secondary_index = self._secondary_hash(key)
+        self.storage[primary_index][secondary_index] = False
+
+    def contains(self, key: int) -> bool:
+        primary_index = self._primary_hash(key)
+
+        if self.storage[primary_index] is None:
+            return False
+
+        secondary_index = self._secondary_hash(key)
+        return self.storage[primary_index][secondary_index]
+
+
+# Your MyHashSet object will be instantiated and called as such:
+# obj = MyHashSet()
+# obj.add(key)
+# obj.remove(key)
+# param_3 = obj.contains(key)