finshed 3.2 Next step I need to add unittest for each question

Author: camilosalazar98

Python/chapter03/3.2 - Stack Min/camilo_solution_3.2.py

@@ -0,0 +1,66 @@
+"""
+Stack Min: How would you design a stack which, in addition to push and pop, has
+a function min which returns the minimum element? Push, pop and min should all
+operate in 0(1) time.
+Hints:#27, #59, #78
+
+
+"""
+class stack:
+    def __init__(self):
+        self.items = []
+
+    def push(self,item):
+        """
+        Add an item to the top of the stack.
+        """
+        self.items.append(item)
+
+    def pop_(self):
+        """
+        Remove the top item from the stack.
+        """
+
+        return self.items.pop()
+
+
+    def peek(self):
+        """
+        Return the top of the stack.
+        """
+        return  self.items[len(self.items)-1]
+
+    def isEmpty(self):
+        """
+        Return true if and only if the stack is empty.
+        """
+        if self.items == None:
+            return True
+        return False
+
+    def print_stack(self):
+        print(self.items)
+
+    def stackMin(self):
+        arr = self.items
+        min = arr[0]
+        for i in range(len(arr)):
+            if min > arr[i]:
+                min = arr[i]
+
+        return min
+
+
+
+st1 = stack()
+st1.push(7)
+st1.push(4)
+st1.push(5)
+st1.push(9)
+st1.push(0)
+st1.push(6)
+st1.push(1)
+st1.push(5)
+st1.push(7)
+st1.print_stack()
+print(st1.stackMin())