done design -1

design-hashset.py

@@ -0,0 +1,35 @@
+class MyHashSet(object):
+
+    def __init__(self):
+        self.data = [False] * (10**6 + 1)
+
+
+    def add(self, key):
+        """
+        :type key: int
+        :rtype: None
+        """
+        self.data[key] = True 
+
+    def remove(self, key):
+        """
+        :type key: int
+        :rtype: None
+        """
+        self.data[key] = False
+
+
+
+    def contains(self, key):
+        """
+        :type key: int
+        :rtype: bool
+        """
+        return self.data[key]
+
+
+# Your MyHashSet object will be instantiated and called as such:
+# obj = MyHashSet()
+# obj.add(key)
+# obj.remove(key)
+# param_3 = obj.contains(key)

design-minstack.py

@@ -0,0 +1,51 @@
+class MinStack(object):
+
+    def __init__(self):
+        self.stack = [] 
+        self.minstack = []
+
+    def push(self, val):
+        """
+        :type val: int
+        :rtype: None
+        """
+        self.stack.append(val)
+
+        #if minstack is empty
+        if not self.minstack:
+            self.minstack.append(val)
+        #if minstack is not empty
+        elif self.minstack[-1] < val:
+            self.minstack.append(self.minstack[-1])
+        else: # if val is less than min
+            self.minstack.append(val)
+
+
+    def pop(self):
+        """
+        :rtype: None
+        """
+        self.stack.pop()
+        self.minstack.pop()
+
+
+    def top(self):
+        """
+        :rtype: int
+        """
+        return self.stack[-1]
+
+
+    def getMin(self):
+        """
+        :rtype: int
+        """
+        return self.minstack[-1]
+
+
+# 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()