diff --git a/Hashset.java b/Hashset.java
new file mode 100644
index 00000000..5e214637
--- /dev/null
+++ b/Hashset.java
@@ -0,0 +1 @@
+(https://leetcode.com/problems/design-hashset/)
\ No newline at end of file
diff --git a/MinStack.java b/MinStack.java
new file mode 100644
index 00000000..04c65f18
--- /dev/null
+++ b/MinStack.java
@@ -0,0 +1,56 @@
+// For push operation O(1) time complexity
+//For peek operatio O(1)
+// pop operation O(1)
+//top and getMIn o(1)
+//Space Complexity o(n) extra space
+
+
+
+
+class MinStack {
+    Stack<Integer> st;
+    Stack<Integer> minStack;
+    int min;
+
+    public MinStack() {
+       st =  new Stack<>();
+       minStack = new Stack<>();
+       min = Integer.MAX_VALUE;
+       minStack.push(min);
+        
+    }
+    
+    public void push(int value) {
+        
+        st.push(value);
+        min = Math.min(min,value);
+        minStack.push(min);
+   
+    }
+    
+    public void pop() {
+        st.pop();
+        minStack.pop();
+        min = minStack.peek();
+        
+    }
+    
+    public int top() {
+      return  st.peek();
+        
+    }
+    
+    public int getMin() {
+     return   minStack.peek();
+        
+    }
+}
+
+/**
+ * Your MinStack object will be instantiated and called as such:
+ * MinStack obj = new MinStack();
+ * obj.push(value);
+ * obj.pop();
+ * int param_3 = obj.top();
+ * int param_4 = obj.getMin();
+ */
\ No newline at end of file