reorganize dir

Signed-off-by: Mia Steinkirch <mia.steinkirch@gmail.com>

ebook_src/abstract_structures/Stack.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+class Stack(object):
+    def __init__(self):
+        self.content = []
+        self.min_array = []
+        self.min = float('inf')
+
+    def push(self, value):
+        if value < self.min:
+            self.min = value
+
+        self.content.append(value)
+        self.min_array.append(self.min)
+
+    def pop(self):
+        if self.content:
+            value = self.content.pop()
+            self.min_array.pop()
+            if self.min_array:
+                self.min = self.min_array[-1]
+            return value
+        else:
+            return 'Empty List. '
+
+    def find_min(self):
+        if self.min_array:
+            return self.min_array[-1]
+        else:
+            return 'No min value for empty list.'
+
+    def size(self):
+        return len(self.content)
+
+    def isEmpty(self):
+        return not bool(self.content)
+
+    def peek(self):
+        if self.content:
+            return self.content[-1]
+        else:
+            print('Stack is empty.')
+
+
+    def __repr__(self):
+        return '{}'.format(self.content)
+
+
+if __name__ == '__main__':
+    q = Stack()
+
+    for i in range(15,20):
+        q.push(i)
+    for i in range(10,5,-1):
+        q.push(i)
+
+
+
+    for i in range(1, 13):
+        print q.pop(), q.find_min()