diff --git a/src/basic_examples/example_args.py b/src/basic_examples/example_args.py
new file mode 100755
index 0000000..299035b
--- /dev/null
+++ b/src/basic_examples/example_args.py
@@ -0,0 +1,17 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+def simple2(a, *args):
+    print args
+
+def simple(*args):
+    print args
+
+def simple3(**kwargs):
+    print kwargs
+
+
+simple(1, 2, 3)
+simple2(1, 2, 3)
+simple3(x=1, y=2)
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_benchmark_decorator.py b/src/basic_examples/example_benchmark_decorator.py
similarity index 95%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/example_benchmark_decorator.py
rename to src/basic_examples/example_benchmark_decorator.py
index 50475b9..749e403 100644
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_benchmark_decorator.py
+++ b/src/basic_examples/example_benchmark_decorator.py
@@ -1,5 +1,7 @@
 #!/usr/bin/env python
 
+__author__ = "bt3"
+
 
 import random
 
diff --git a/src/basic_examples/example_comp_lists.py b/src/basic_examples/example_comp_lists.py
new file mode 100644
index 0000000..f5c641c
--- /dev/null
+++ b/src/basic_examples/example_comp_lists.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+a = [3, 4, 5, 6, 7]
+
+
+# Filter elements greater than 4
+
+# Bad:
+
+b = []
+for i in a:
+    if i > 4:
+        b.append(i)
+print b
+
+# Good:
+print [i for i in a if i > 4]
+
+# Or:
+print filter(lambda x: x > 4, a)
+
+
+# Add three to all list members:
+
+# Bad
+b = []
+for i in range(len(a)):
+    b.append(a[i] + 3)
+print b
+
+# Good:
+print [i + 3 for i in a]
+
+# Or:
+print map(lambda i: i + 3, a)
\ No newline at end of file
diff --git a/src/basic_examples/example_decorators.py b/src/basic_examples/example_decorators.py
new file mode 100755
index 0000000..a64b299
--- /dev/null
+++ b/src/basic_examples/example_decorators.py
@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
+def logger(func):
+    def inner(*args): #1
+        print "Arguments were: {0}".format(args)
+        return func(*args)
+    return inner
+
+@logger
+def foo(x, y):
+    return x+y
+
+print foo(1, 2)
+
+
+def sum(func):
+    s = 0
+    for i in func():
+        s += i
+    return s
+
+@sum
+def interate():
+    a = []
+    for i in range(10):
+        a.append(i)
+    return a
+
+print interate
+
+# which is the same as
+def interate():
+    a = []
+    for i in range(10):
+        a.append(i)
+    return a
+
+print sum(interate)
\ No newline at end of file
diff --git a/src/basic_examples/example_generator.py b/src/basic_examples/example_generator.py
new file mode 100644
index 0000000..8256b90
--- /dev/null
+++ b/src/basic_examples/example_generator.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+def interate(x):
+    for i in range(x):
+        yield i
+
+def gen1():
+    a =  interate(10)
+    print a.next()
+    print a.next()
+    print a.next()
+
+
+def reverse(data):
+    for i in range(len(data)-1, -1, -1):
+        yield data[i]
+
+def gen2():
+    for c in reverse('awesome'):
+        print c
+
+if __name__ == '__main__':
+    gen1()
+    gen2()
diff --git a/src/basic_examples/example_lambda.py b/src/basic_examples/example_lambda.py
new file mode 100644
index 0000000..34ddec3
--- /dev/null
+++ b/src/basic_examples/example_lambda.py
@@ -0,0 +1,7 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+test = lambda x: x**2
+print test(3)
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_logging.py b/src/basic_examples/example_logging.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/example_logging.py
rename to src/basic_examples/example_logging.py
diff --git a/src/basic_examples/example_open_files.py b/src/basic_examples/example_open_files.py
new file mode 100644
index 0000000..28d03e6
--- /dev/null
+++ b/src/basic_examples/example_open_files.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+filename = raw_input('Enter a file name: ')
+try:
+    f = open(filename, "r")
+except:
+    print 'There is no file named', filename
+
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/export_pickle.py b/src/basic_examples/example_pickle.py
similarity index 58%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/export_pickle.py
rename to src/basic_examples/example_pickle.py
index 2d60e52..2a863ee 100644
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/export_pickle.py
+++ b/src/basic_examples/example_pickle.py
@@ -1,11 +1,33 @@
 #!/usr/bin/env python
 
+__author__ = "bt3"
 
 
-""" simple example of how to use pickle to export files """
-
 import pickle
 
+def import_pickle(filename):
+    fh = None
+    try:
+        fh = open(filename, "rb")
+        mydict2 = pickle.load(fh)
+        return mydict2
+
+    except (EnvironmentError) as err:
+        print ("{0}: import error: {0}".format(os.path.basename(sys.arg[0]), err))
+        return false
+
+    finally:
+        if fh is not None:
+            fh.close()
+
+
+def test_import_pickle():
+    pkl_file = 'test.dat'
+    mydict = import_pickle(pkl_file)
+    print(mydict)
+
+
+
 def export_pickle(data, filename='test.dat', compress=False):
 
     fh = None
@@ -33,3 +55,4 @@ def test_export_pickle():
 
 if __name__ == '__main__':
     test_export_pickle()
+    test_import_pickle()
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_queue.py b/src/basic_examples/example_queue.py
similarity index 71%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/example_queue.py
rename to src/basic_examples/example_queue.py
index 2df713b..b51548f 100755
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_queue.py
+++ b/src/basic_examples/example_queue.py
@@ -1,4 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 import Queue
 
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_socket.py b/src/basic_examples/example_socket.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/example_socket.py
rename to src/basic_examples/example_socket.py
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_string_format.py b/src/basic_examples/example_string_format.py
similarity index 78%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/example_string_format.py
rename to src/basic_examples/example_string_format.py
index a5c03b6..b13add5 100644
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_string_format.py
+++ b/src/basic_examples/example_string_format.py
@@ -1,3 +1,8 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
 foo = 'foo'
 bar = 'bar'
 
diff --git a/src/basic_examples/example_subprocess.py b/src/basic_examples/example_subprocess.py
new file mode 100644
index 0000000..b845ca4
--- /dev/null
+++ b/src/basic_examples/example_subprocess.py
@@ -0,0 +1,8 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+import subprocess,os
+
+os.system('ls')
+subprocess.call(['ls', '-1'], shell=True)
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_telnet.py b/src/basic_examples/example_telnet.py
similarity index 93%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/example_telnet.py
rename to src/basic_examples/example_telnet.py
index 2752f83..2c46254 100644
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_telnet.py
+++ b/src/basic_examples/example_telnet.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 
 
-__author__ = "bt3gl"
+__author__ = "bt3"
 
 
 from telnetlib import Telnet
diff --git a/src/basic_examples/example_testing.py b/src/basic_examples/example_testing.py
new file mode 100644
index 0000000..5e900f2
--- /dev/null
+++ b/src/basic_examples/example_testing.py
@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
+def test_doctest():
+    '''
+    >>> 1 == 1
+    False
+    '''
+    pass
+
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()
+
+#####
+
+import unittest
+
+class BasicsTestCase(unittest.TestCase):
+
+    def test_find_name(self):
+        self.assertTrue(1 == 1)
+        self.assertFalse(1 == 2)
+
+if __name__ == '__main__':
+    unittest.main()
+
+
+
+#####
+
+# content of test_example.py, run with $ py.test
+#
+# run tests over the directory
+# $ nosetest
+
+
+def func(x):
+    return x + 1
+
+def test_answer():
+    assert func(3) == 4
+
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_threads.py b/src/basic_examples/example_threads.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/basic_examples/example_threads.py
rename to src/basic_examples/example_threads.py
diff --git a/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/queue_with_stack.py b/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/queue_with_stack.py
index 193aac7..d74ccf8 100755
--- a/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/queue_with_stack.py
+++ b/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/queue_with_stack.py
@@ -1,25 +1,27 @@
-class Queue():
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+class Queue(object):
     def __init__(self):
-        self.in_ = []
-        self.out = []
+        self.enq = []
+        self.deq = []
 
-    def enqueue(self, item):
-        self.in_.append(item)
+    def enqueue(self, value):
+        self.enq.append(value)
 
-    def deque(self):
-        if not self.out:
-            while self.in_:
-                self.out.append(self.in_.pop())
+    def dequeue(self):
+        if not self.deq:
+            while self.enq:
+                self.deq.append(self.enq.pop())
+        return self.deq.pop()
 
-        return self.out.pop()
+if __name__ == '__main__':
+    q = Queue()
 
+    for i in range(1,10):
+        q.enqueue(i)
 
-
-
-
-
-q = Queue()
-for i in range(10):
-    q.enqueue(i)
-for i in range(10):
-    print(q.deque())
\ No newline at end of file
+    for i in range(1, 10):
+        print q.dequeue()
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/stack_with_minumum.py b/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/stack_with_minumum.py
new file mode 100755
index 0000000..873ab55
--- /dev/null
+++ b/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/stack_with_minumum.py
@@ -0,0 +1,48 @@
+#!/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.'
+
+
+
+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()
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/stack_with_minumum.txt b/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/stack_with_minumum.txt
deleted file mode 100755
index 5985d61..0000000
--- a/src/extra_interview_problems/glassdoor/2014/abstract_strucutres/stack_with_minumum.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-Another way:
-
-Store two stacks, one of which contains all of the items in the stack and one of which is a stack of minima.
-
-To push an element, push it onto the first stack. Check whether it is smaller than the top item on the second stack, if so, push it onto the second stack.
-
-To pop an item, pop it from the first stack. If it is the top element, simply return the element on the top of the second stack.
-
-O(1)...
diff --git a/src/extra_interview_problems/glassdoor/2014/advanced/lru_cache.py b/src/extra_interview_problems/glassdoor/2014/advanced/lru_cache.py
index 5938ac0..11b451e 100644
--- a/src/extra_interview_problems/glassdoor/2014/advanced/lru_cache.py
+++ b/src/extra_interview_problems/glassdoor/2014/advanced/lru_cache.py
@@ -1,4 +1,7 @@
-#!/bin/python3
+#!/usr/bin/env python3
+
+__author__ = "bt3"
+
 
 from functools import lru_cache
 
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_args.py b/src/extra_interview_problems/glassdoor/2014/basic_examples/example_args.py
deleted file mode 100755
index e6e70c1..0000000
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_args.py
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/usr/bin/python
-
-def simple2(a, *args):
-    print args
-
-def simple(*args):
-    print args
-
-def simple3(**kwargs):
-    print kwargs
-
-
-simple(1, 2, 3)
-simple2(1, 2, 3)
-simple3(x=1, y=2)
-
-
-def logger(func):
-    def inner(*args): #1
-        print "Arguments were: {0}".format(args)
-        return func(*args)
-    return inner
-
-@logger
-def foo(x, y):
-    return x+y
-
-print foo(1, 2)
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_comp_lists.py b/src/extra_interview_problems/glassdoor/2014/basic_examples/example_comp_lists.py
deleted file mode 100644
index cb1fd16..0000000
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_comp_lists.py
+++ /dev/null
@@ -1,26 +0,0 @@
-Bad:
-
-# Filter elements greater than 4
-a = [3, 4, 5]
-b = []
-for i in a:
-    if i > 4:
-        b.append(i)
-Good:
-
-a = [3, 4, 5]
-b = [i for i in a if i > 4]
-# Or:
-b = filter(lambda x: x > 4, a)
-Bad:
-
-# Add three to all list members.
-a = [3, 4, 5]
-for i in range(len(a)):
-    a[i] += 3
-Good:
-
-a = [3, 4, 5]
-a = [i + 3 for i in a]
-# Or:
-a = map(lambda i: i + 3, a)
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_generator.py b/src/extra_interview_problems/glassdoor/2014/basic_examples/example_generator.py
deleted file mode 100644
index 508803a..0000000
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_generator.py
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/usr/bin/env python
-
-__author__ = "bt3"
-
-" Example of generator."
-
-def reverse(data):
-    for i in range(len(data)-1, -1, -1):
-        yield data[i]
-
-if __name__ == '__main__':
-    for c in reverse('awesome'):
-        print c
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_lambda.py b/src/extra_interview_problems/glassdoor/2014/basic_examples/example_lambda.py
deleted file mode 100644
index 622ccae..0000000
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_lambda.py
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/usr/bin/env python
-
-teste = lambda x: x**2
-print teste(3)
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_testing.py b/src/extra_interview_problems/glassdoor/2014/basic_examples/example_testing.py
deleted file mode 100644
index 014f600..0000000
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/example_testing.py
+++ /dev/null
@@ -1,65 +0,0 @@
--------------------------------------------
-'''
->>> 1 == 1
-False
-'''
-
-if __name__ == '__main__':
-    import doctest
-    doctest.testmod()
-
--------------------------------------------
-
-import unittest
-
-class BasicsTestCase(unittest.TestCase):
-
-    def test_find_name(self):
-        self.assertTrue(1 == 1)
-        self.assertFalse(1 == 2)
-
-if __name__ == '__main__':
-    unittest.main()
-
--------------------------------------------
-
-# content of test_example.py, run with $ py.test
-
-def func(x):
-    return x + 1
-
-def test_answer():
-    assert func(3) == 4
-
--------------------------------------------
-
-# run tests over the directory
-$ nosetest
-
----------------------------------------------
-
-filename = raw_input('Enter a file name: ')
-try:
-    f = open(filename, "r")
-except:
-    print 'There is no file named', filename
-
-raise Exception('Invalid config file: expecting keys "aws_access_key", "aws_secret_key", "bucket"')
-g = lambda x: x ** 2
-
-try:
-    operation, filename = sys.argv[1:]
-except ValueError:
-    print __doc__
-    sys.exit(2)
-
-subprocess.call()
-try:
-    response = urllib2.urlopen()
-
------------------------------------------------
-
-import subprocess,os
-
-os.system('ls')
-subprocess.call(['ls', '-1'], shell=True)
diff --git a/src/extra_interview_problems/glassdoor/2014/basic_examples/import_pickle.py b/src/extra_interview_problems/glassdoor/2014/basic_examples/import_pickle.py
deleted file mode 100644
index 32cd53c..0000000
--- a/src/extra_interview_problems/glassdoor/2014/basic_examples/import_pickle.py
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/usr/bin/env python
-
-
-__author__ = "Mari Wahl"
-__email__ = "marina.w4hl@gmail.com"
-
-
-""" an example of using pickle for importing data from files """
-
-
-import pickle
-
-def import_pickle(filename):
-    fh = None
-    try:
-        fh = open(filename, "rb")
-        mydict2 = pickle.load(fh)
-        return mydict2
-
-    except (EnvironmentError) as err:
-        print ("{0}: import error: {0}".format(os.path.basename(sys.arg[0]), err))
-        return false
-
-    finally:
-        if fh is not None:
-            fh.close()
-
-
-def test_import_pickle():
-    pkl_file = 'test.dat'
-    mydict = import_pickle(pkl_file)
-    print(mydict)
-
-
-if __name__ == '__main__':
-    test_import_pickle()
diff --git a/src/extra_interview_problems/glassdoor/2014/bitwise/clear_bits.py b/src/extra_interview_problems/glassdoor/2014/bitwise/clear_bits.py
index 36d477b..5297b74 100755
--- a/src/extra_interview_problems/glassdoor/2014/bitwise/clear_bits.py
+++ b/src/extra_interview_problems/glassdoor/2014/bitwise/clear_bits.py
@@ -1,4 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 ''' Clear a bit in a binary number.
     Like the reverse of set bit:
diff --git a/src/extra_interview_problems/glassdoor/2014/bitwise/find_bit_len.py b/src/extra_interview_problems/glassdoor/2014/bitwise/find_bit_len.py
index 03812ab..9961241 100755
--- a/src/extra_interview_problems/glassdoor/2014/bitwise/find_bit_len.py
+++ b/src/extra_interview_problems/glassdoor/2014/bitwise/find_bit_len.py
@@ -1,4 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 ''' Find how many bits a int has:
     1) Start with a mask of 1
diff --git a/src/extra_interview_problems/glassdoor/2014/bitwise/get_bit.py b/src/extra_interview_problems/glassdoor/2014/bitwise/get_bit.py
index 994734f..b212316 100755
--- a/src/extra_interview_problems/glassdoor/2014/bitwise/get_bit.py
+++ b/src/extra_interview_problems/glassdoor/2014/bitwise/get_bit.py
@@ -1,4 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 ''' Get a bit in a binary number:
     1) Shifts 1 over by i bits
diff --git a/src/extra_interview_problems/glassdoor/2014/bitwise/num_bits_to_convert_2_nums.py b/src/extra_interview_problems/glassdoor/2014/bitwise/num_bits_to_convert_2_nums.py
index 236f00f..3447d35 100755
--- a/src/extra_interview_problems/glassdoor/2014/bitwise/num_bits_to_convert_2_nums.py
+++ b/src/extra_interview_problems/glassdoor/2014/bitwise/num_bits_to_convert_2_nums.py
@@ -1,4 +1,7 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 ''' This method returns the number of bits that are necessary to change to convert two
     numbers A and B:
diff --git a/src/extra_interview_problems/glassdoor/2014/bitwise/set_bit.py b/src/extra_interview_problems/glassdoor/2014/bitwise/set_bit.py
index 53896c1..0e78852 100755
--- a/src/extra_interview_problems/glassdoor/2014/bitwise/set_bit.py
+++ b/src/extra_interview_problems/glassdoor/2014/bitwise/set_bit.py
@@ -1,4 +1,9 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
 ''' Set a bit in a binary number:
     1) Shifts 1 over by i bits
     2) make an OR with the number, only the value at bit i will change and all the others bit
diff --git a/src/extra_interview_problems/glassdoor/2014/bitwise/swap_in_place.py b/src/extra_interview_problems/glassdoor/2014/bitwise/swap_in_place.py
index d9a3e60..6745132 100755
--- a/src/extra_interview_problems/glassdoor/2014/bitwise/swap_in_place.py
+++ b/src/extra_interview_problems/glassdoor/2014/bitwise/swap_in_place.py
@@ -1,4 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 '''
     swapping values in place without extra memory
diff --git a/src/extra_interview_problems/glassdoor/2014/bitwise/update_bit.py b/src/extra_interview_problems/glassdoor/2014/bitwise/update_bit.py
index 41d3bd6..c31d713 100755
--- a/src/extra_interview_problems/glassdoor/2014/bitwise/update_bit.py
+++ b/src/extra_interview_problems/glassdoor/2014/bitwise/update_bit.py
@@ -1,4 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 ''' This method merges set bit and clean bit:
     1) first clear the bit at i using a mask such as 1110111
diff --git a/src/extra_interview_problems/glassdoor/2014/design/design_pattern.txt b/src/extra_interview_problems/glassdoor/2014/design/design_pattern.txt
deleted file mode 100755
index 16486fe..0000000
--- a/src/extra_interview_problems/glassdoor/2014/design/design_pattern.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-			 DESIGN PATTERNS
-                    ------------------------
-
-LISTENER/OBSERVER:
------------------
-
-- Example: a GUI as a listener to several objects. For any change in the state, it would update the display.
-
-
-SINGLETON PATTERN:
------------------
-
-- To make sure that there is exactly one instance of something in the program.
-
-
-MODEL-VIEW-CONTROLLER:
-----------------------
-
-- Design commonly used in user interfaces. The goal is to keep the data separate from the interface.
-- Separate programming entities to store the data (model), display the data (view) and modify the data (controlle).
-- The view usually makes heavy use of listeners to listen to changes and events in the model or controller.
diff --git a/src/extra_interview_problems/glassdoor/2014/design/design_text_editor.txt b/src/extra_interview_problems/glassdoor/2014/design/design_text_editor.txt
deleted file mode 100755
index a55170d..0000000
--- a/src/extra_interview_problems/glassdoor/2014/design/design_text_editor.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-			DESIGN A TEXT EDITOR
-		-------------------------------------
-
-- Classes to set up the text editor: classes for the GUI, formatting, saving/loading files, handling input.
-
-- Use inheritance where it makes sense.
-
-- Use design patterns (such as MVC, listener, singleton).
diff --git a/src/extra_interview_problems/glassdoor/2014/design/example_decorator.py b/src/extra_interview_problems/glassdoor/2014/design/example_decorator.py
deleted file mode 100755
index ee41f01..0000000
--- a/src/extra_interview_problems/glassdoor/2014/design/example_decorator.py
+++ /dev/null
@@ -1,39 +0,0 @@
-#!/usr/bin/python
-
-
-# testing generator
-
-def interate(x):
-    for i in range(x):
-        yield i
-
-a =  interate(10)
-
-print a.next()
-print a.next()
-print a.next()
-
-# testing decorator
-
-def sum(func):
-    s = 0
-    for i in func():
-        s += i
-    return s
-
-@sum
-def interate():
-    a = []
-    for i in range(10):
-        a.append(i)
-    return a
-
-print interate
-
-def interate():
-    a = []
-    for i in range(10):
-        a.append(i)
-    return a
-
-print sum(interate)
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/anagrams_hash_table.txt b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/anagrams_hash_table.txt
index 7f1f14c..4549df1 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/anagrams_hash_table.txt
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/anagrams_hash_table.txt
@@ -1,3 +1,8 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
 Given an english word in the form of a string, how can you quickly find all valid anagrams for that string?
 
 First you go through each word in the dictionary, sort the letters of the word and use this as a key in a Hash Table. O(nln n).
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/balance.txt b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/balance.txt
index 6f081f1..0a66673 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/balance.txt
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/balance.txt
@@ -1,3 +1,8 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
 This is the classic "you have 8 balls/coins, which are the same weight, except for one which is slightly heavier than the others. You also have an old-style balance. What is the fewest number of weighings to find the heavy coin/ball?
 
 Answer: 2! You need to use every information available:
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_2_numbers_array_sum.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_2_numbers_array_sum.py
index 2a9f7df..d0fb7bf 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_2_numbers_array_sum.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_2_numbers_array_sum.py
@@ -1,5 +1,6 @@
-#!/bin/python
+#!/usr/bin/env python
 
+__author__ = "bt3"
 
 """
 Given an integer x and an unsorted array of integers, describe an algorithm to
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_if_anagrams.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_if_anagrams.py
index b2cf38f..c7d94e5 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_if_anagrams.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_if_anagrams.py
@@ -1,4 +1,7 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 """ find whether two words are anagrams. Since sets do not count occurency, and sorting is O(nlogn)
 we will use hash tables. We scan the first string and add all the character occurences. Then we
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_palindrome.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_palindrome.py
deleted file mode 100644
index d17116b..0000000
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/check_palindrome.py
+++ /dev/null
@@ -1,38 +0,0 @@
-#!/bin/python
-
-''' Check if palindrome'''
-
-
-def check_pal(string):
-    string = "".join(string.split(' '))
-    p1, p2 = 0, len(string)-1
-    pal = True
-    while p1 < p2:
-        if string[p1] != string[p2]:
-            pal = False
-            break
-        p1+=1
-        p2-=1
-    return pal
-
-
-def check_pal2(string):
-    string = "".join(string.split(' '))
-    if len(string)<2:
-        return True
-    if string[0] != string[-1]:
-        return False
-    return check_pal2(string[1:-1])
-
-
-if __name__ == '__main__':
-    string1 = "borrow or rob"
-    string2 = " draw ward"
-    string3 = "google is fun"
-    print(check_pal(string1))
-    print(check_pal(string2))
-    print(check_pal(string3))
-    print
-    print(check_pal2(string1))
-    print(check_pal2(string2))
-    print(check_pal2(string3))
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_combinations_strings.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/combinations.py
similarity index 69%
rename from src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_combinations_strings.py
rename to src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/combinations.py
index c0ea950..a7cd99f 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_combinations_strings.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/combinations.py
@@ -1,16 +1,19 @@
-#!/usr/bin/python
-#
-''' give all the combinations of a str or list '''
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 
 def comb_str(l1):
+
     if len(l1) < 2:
         return l1
+
     result = []
     for i, c in enumerate(l1):
         result.append(c)
         for comb in comb_str(l1[i+1:]):
-            result.append(c + "".join(comb))
+            result.append(c + comb)
+
     return result
 
 
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/decide_if_permutation.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/decide_if_permutation.py
deleted file mode 100644
index da830da..0000000
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/decide_if_permutation.py
+++ /dev/null
@@ -1,22 +0,0 @@
-#!/usr/bin/env python
-
-def define_if_permutation(word1, word2):
-    """
-    >>> define_if_permutation('hello', 'lolhe')
-    True
-    >>> define_if_permutation('stripe', 'triipe')
-    False
-    """
-    if sorted(word1) == sorted(word2):
-        return True
-    else:
-        return False
-
-
-
-
-
-
-if __name__ == '__main__':
-    import doctest
-    doctest.testmod()
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/delete_duplicate_char_str.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/delete_duplicate_char_str.py
index 5f962ae..898935c 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/delete_duplicate_char_str.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/delete_duplicate_char_str.py
@@ -1,23 +1,36 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 '''  find and delete all the duplicate characters in a string '''
 
 
 import string
 
-def delete_unique_word(str1):
-    table_c = { key : 0  for key in string.ascii_lowercase}
-    for i in str1:
-        table_c[i] += 1
-    for key, value in table_c.items():
-        if value > 1:
-            str1 = str1.replace(key, "")
+from collections import Counter
+def delete_unique(str1):
+    '''
+    >>> delete_unique("Trust no one")
+    'on'
+    >>> delete_unique("Mulder?")
+    ''
+    '''
 
-    return str1
+    str_strip = ''.join(str1.split())
+    repeat = Counter()
+
+    for c in str_strip:
+        repeat[c] += 1
+
+    result = ''
+    for c, count in repeat.items():
+        if count > 1:
+            result += c
+
+    return result
 
 
 
 if __name__ == '__main__':
-    str1 = "google"
-    print delete_unique_word(str1) # == 'le'
-
+    import doctest
+    doctest.testmod()
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/fibonacci.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/fibonacci.py
index b6362bf..da5b01b 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/fibonacci.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/fibonacci.py
@@ -1,9 +1,7 @@
 #!/usr/bin/env python
 
-
 __author__ = "bt3"
 
- ''' understanding generators'''
 
 def fib_generator():
     a, b = 0, 1
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_all_permutations_string.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_all_permutations_string.py
deleted file mode 100755
index 8d80954..0000000
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_all_permutations_string.py
+++ /dev/null
@@ -1,81 +0,0 @@
-#!/usr/bin/python
-
-
-def find_permutations(s):
-    if len(s) < 2: return s
-    res = []
-    for i, c in enumerate(s):
-        for perm in find_permutations(s[:i] + s[i+1:]):
-            res.append(c + "".join(perm))
-    return res
-
-
-def fpc(s):
-    return [s] if len(s)<2 else [c+p for i,c in enumerate(s) for p in fpc(s[:i]+s[i+1:])]
-
-
-def find_permutations_stdlib(s):
-    from itertools import permutations
-    return [''.join(p) for p in permutations(s)]
-
-
-def find_permutations2(s):
-    if len(s) < 2: return s
-    res = []
-    for i in range(len(s)):
-        for perm in find_permutations2(s[:i] + s[i+1:]):
-            res.append(s[i] + perm)
-    return res
-
-
-def verify_if_perm(s1, s2):
-    if len(s1) != len(s2): return False
-    s1 = sorted(s1)
-    s2 = sorted(s2)
-    return s1 == s2
-
-
-from collections import Counter
-def verify_if_perm2(s1, s2): # like anagram
-    if len(s1) != len(s2): return False
-    dict_aux = Counter()
-    for c in s1:
-        dict_aux[c] += 1
-    for c in s2:
-        dict_aux[c] -= 1
-    for item in dict_aux:
-        if dict_aux[item]:
-            return False
-    return True
-
-
-
-if __name__ == '__main__':
-    s1 = 'ufyfbufyfb'
-    s2 = 'buffybuffy'
-    s3 = 'uuyfbuuyfb'
-    s4 = ''
-
-    print(verify_if_perm(s1, s2))
-    print(verify_if_perm(s1, s3))
-    print(verify_if_perm(s1, s4))
-    print
-    print(verify_if_perm2(s1, s2))
-    print(verify_if_perm2(s1, s3))
-    print(verify_if_perm2(s1, s4))
-
-    print
-
-    s = 'hat'
-    print find_permutations(s)
-    print fpc(s)
-    print find_permutations_stdlib(s)
-    print find_permutations2(s)
-    print
-    print find_permutations(s4)
-    print fpc(s4)
-    print find_permutations_stdlib(s4)
-    print find_permutations2(s4)
-
-
-
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_is_substr.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_is_substr.py
index 3fcc0a7..b28cfe7 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_is_substr.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_is_substr.py
@@ -1,4 +1,7 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 def isSubstr(s1, s2):
     if s1 in s2 or s2 in s1: return True
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_unique_char.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_unique_char.py
index 087ac4a..3e88c46 100644
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_unique_char.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_if_unique_char.py
@@ -1,5 +1,9 @@
 #!/usr/bin/env python
 
+__author__ = "bt3"
+
+
+
 import collections
 
 def find_if_unique_chars(word):
@@ -13,11 +17,13 @@ def find_if_unique_chars(word):
     unique = True
 
     counter = collections.Counter()
+
     for c in word:
         if not counter[c]:
             counter[c] += 1
         else:
             unique = False
+
     return unique
 
 
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_largest_sum.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_largest_sum.py
index bc106d4..a26e787 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_largest_sum.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_largest_sum.py
@@ -1,4 +1,8 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
 
 '''You are given an array of integers (both positive and negative). Find the contiguous
 sequence with the largest sum. Return the sum.'''
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_non_repeating_number.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_non_repeating_number.py
index b440014..3c2d932 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_non_repeating_number.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_non_repeating_number.py
@@ -1,4 +1,7 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 from collections import defaultdict
 
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_sum_ints.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_sum_ints.py
index 480a46f..85239bf 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_sum_ints.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/find_sum_ints.py
@@ -1,7 +1,8 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
-'''Design an algorithm to find all pairs of integers within an array
-    which sum to a specified value.'''
 
 from collections import defaultdict
 
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_gcd.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_gcd.py
index 12163d7..d9dfa4c 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_gcd.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_gcd.py
@@ -1,11 +1,14 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 
 def finding_gcd(a, b):
     ''' implements the greatest common divider algorithm '''
     while(b != 0):
         result = b
-        a, b = b, a % b        
+        a, b = b, a % b
     return result
 
 
@@ -20,7 +23,7 @@ if __name__ == '__main__':
 
 
 
-    
-    
-    
-    
+
+
+
+
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_if_prime.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_if_prime.py
index 2c2c447..4abf97e 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_if_prime.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/finding_if_prime.py
@@ -1,6 +1,8 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
 
 import math
 import random
@@ -13,7 +15,7 @@ def finding_prime(number):
         if num % x == 0:
             return False
     return True
-       
+
 
 def finding_prime_sqrt(number):
     ''' find whether a number is prime as soon as it rejects all candidates up to sqrt(n) '''
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/generate_prime.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/generate_prime.py
index a008b4c..7f6f828 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/generate_prime.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/generate_prime.py
@@ -1,6 +1,7 @@
-#!/usr/bin/python3
-# mari von steinkirch @2013
-# steinkirch at gmail
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 import math
 import random
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/get_float_rep_bin.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/get_float_rep_bin.py
index 5c62268..5f037dd 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/get_float_rep_bin.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/get_float_rep_bin.py
@@ -1,4 +1,7 @@
-#!/usr/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 ''' Given a real number between 0 and 1 (eg: 0.72), this method print the binary
     representation. If the Number cannot be represented accurately in binary, with at
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/interserction_two_arrays.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/interserction_two_arrays.py
index 485634a..5079030 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/interserction_two_arrays.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/interserction_two_arrays.py
@@ -1,7 +1,6 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
-__author__ = "Mari Wahl"
-__email__ = "marina.w4hl@gmail.com"
+__author__ = "bt3"
 
 
 
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/max_subarray_stocks.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/max_subarray_stocks.py
index b3acaf9..f79e87d 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/max_subarray_stocks.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/max_subarray_stocks.py
@@ -1,3 +1,9 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
 def beating_stock(array):
 
     imin = 0
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/number_of_zeros_factorial.txt b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/number_of_zeros_factorial.txt
index 317bfa1..066451c 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/number_of_zeros_factorial.txt
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/number_of_zeros_factorial.txt
@@ -1,3 +1,9 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
 How to know how many 0 are in 100!
 
 You look for the primes that multiply to 10, i.e. 2 and 5.
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/permutations.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/permutations.py
new file mode 100755
index 0000000..14c4134
--- /dev/null
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/permutations.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
+def perm(str1):
+    '''
+    >>> perm('123')
+    ['123', '132', '231', '213', '312', '321']
+    '''
+
+    if len(str1) < 2:
+        return str1
+
+    res = []
+    for i, c in enumerate(str1):
+        for cc in perm(str1[i+1:] + str1[:i]):
+            res.append(c + cc)
+    return res
+
+
+def perm2(str1):
+    '''
+    >>> perm2('123')
+    ['123', '132', '213', '231', '312', '321']
+    '''
+    from itertools import permutations
+    return [''.join(p) for p in permutations(str1)]
+
+
+def ispermutation(s1, s2):
+    '''
+    >>> ispermutation('231', '123')
+    True
+    >>> ispermutation('231', '153')
+    False
+    '''
+
+    from collections import Counter
+    aux = Counter()
+    for i in s1:
+        aux[i] += 1
+    for i in s2:
+        aux[i] -= 1
+    for v in aux.values():
+        if v != 0:
+            return False
+    return True
+
+
+
+
+def ispermutation2(s1, s2):
+    '''
+    >>> ispermutation2('231', '123')
+    True
+    >>> ispermutation2('231', '153')
+    False
+    '''
+    if sorted(s1) == sorted(s2):
+        return True
+    else:
+        return False
+
+
+
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/ransom_note.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/ransom_note.py
index c81a680..14cc1db 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/ransom_note.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/ransom_note.py
@@ -1,3 +1,9 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
 from collections import Counter
 
 def check_if_ransom_note(magazines, note):
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/rev_string.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/rev_string.py
index c3da5be..64b09ce 100644
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/rev_string.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/rev_string.py
@@ -1,4 +1,8 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
 
 ''' Reverting a string '''
 
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words.py
index 24c72ec..593a6d9 100644
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words.py
@@ -1,5 +1,9 @@
 #!/usr/bin/env python
 
+__author__ = "bt3"
+
+
+
 def invert_word(word):
     """
     >>> invert_word('stripe is awesome')
diff --git a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words_sentence.py b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words_sentence.py
index 5904109..7064468 100755
--- a/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words_sentence.py
+++ b/src/extra_interview_problems/glassdoor/2014/math_arrays_and_strings/reverse_words_sentence.py
@@ -1,5 +1,6 @@
-#!/usr/bin python
+#!/usr/bin/env python
 
+__author__ = "bt3"
 
 
 def reversing_words_setence_py(s):
diff --git a/src/extra_interview_problems/glassdoor/2014/sorting_and_searching/deck_shuffling.txt b/src/extra_interview_problems/glassdoor/2014/sorting_and_searching/deck_shuffling.txt
deleted file mode 100755
index 2f9e063..0000000
--- a/src/extra_interview_problems/glassdoor/2014/sorting_and_searching/deck_shuffling.txt
+++ /dev/null
@@ -1,3 +0,0 @@
-How to shuffle an array or a deck of cards so each shuffle has the same probability?
-
-go thru the array shuffling each element with any random element after that.
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/sorting_and_searching/quick_sort.py b/src/extra_interview_problems/glassdoor/2014/sorting_and_searching/quick_sort.py
index 77034d0..0b99675 100644
--- a/src/extra_interview_problems/glassdoor/2014/sorting_and_searching/quick_sort.py
+++ b/src/extra_interview_problems/glassdoor/2014/sorting_and_searching/quick_sort.py
@@ -1,17 +1,27 @@
-#!/bin/python
+#!/usr/bin/env python
 
-''' Quick sort an array '''
+__author__ = "bt3"
 
 
-def quick_sort(arr):
-    if len(arr) < 2: return arr
-    piv = len(arr)//2
-    left = [x for i, x in enumerate(arr) if x <= arr[piv] and i != piv]
-    right = [x for i, x in enumerate(arr) if x > arr[piv] and i != piv]
-    return quick_sort(left) + [arr[piv]] + quick_sort(right)
+def qs(array):
+    '''
+    >>> qs([4,1,6,2,7,9,3])
+    [1, 2, 3, 4, 6, 7, 9]
+    '''
+    if len(array) < 2:
+        return array
 
+    piv = len(array)//2
+    piv_element = array[piv]
+    new_array = array[:piv] + array[piv+1:]
+
+    left  = [a for a in new_array if a <= piv_element]
+    right = [a for a in new_array if a > piv_element]
+
+
+    return qs(left) + [array[piv]] + qs(right)
 
 
 if __name__ == '__main__':
-    arr = [8, 5, 2, 6, 1, 2, 9, 4]
-    print(quick_sort(arr))
\ No newline at end of file
+    import doctest
+    doctest.testmod()
\ No newline at end of file
diff --git a/src/extra_interview_problems/glassdoor/2014/trees_paths/binary_search_tree.py b/src/extra_interview_problems/glassdoor/2014/trees/binary_search_tree.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/trees_paths/binary_search_tree.py
rename to src/extra_interview_problems/glassdoor/2014/trees/binary_search_tree.py
diff --git a/src/extra_interview_problems/glassdoor/2014/trees_paths/binary_tree.py b/src/extra_interview_problems/glassdoor/2014/trees/binary_tree.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/trees_paths/binary_tree.py
rename to src/extra_interview_problems/glassdoor/2014/trees/binary_tree.py
diff --git a/src/extra_interview_problems/glassdoor/2014/trees_paths/check_whether_bst.py b/src/extra_interview_problems/glassdoor/2014/trees/check_whether_bst.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/trees_paths/check_whether_bst.py
rename to src/extra_interview_problems/glassdoor/2014/trees/check_whether_bst.py
diff --git a/src/extra_interview_problems/glassdoor/2014/trees_paths/lowest_common_ancestor.py b/src/extra_interview_problems/glassdoor/2014/trees/lowest_common_ancestor.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/trees_paths/lowest_common_ancestor.py
rename to src/extra_interview_problems/glassdoor/2014/trees/lowest_common_ancestor.py
diff --git a/src/extra_interview_problems/glassdoor/2014/trees_paths/transversal_BST_ancestor.py b/src/extra_interview_problems/glassdoor/2014/trees/transversal_BST_ancestor.py
similarity index 100%
rename from src/extra_interview_problems/glassdoor/2014/trees_paths/transversal_BST_ancestor.py
rename to src/extra_interview_problems/glassdoor/2014/trees/transversal_BST_ancestor.py
diff --git a/src/extra_interview_problems/glassdoor/2015/alpha_permutation.py b/src/extra_interview_problems/glassdoor/2015/alpha_permutation.py
index a67a534..1c0ff96 100644
--- a/src/extra_interview_problems/glassdoor/2015/alpha_permutation.py
+++ b/src/extra_interview_problems/glassdoor/2015/alpha_permutation.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 ''' Write code to generate all possible case permutations of a given
 lower-cased string
diff --git a/src/extra_interview_problems/glassdoor/2015/anagram.py b/src/extra_interview_problems/glassdoor/2015/anagram.py
index 5f49364..2cb2efc 100644
--- a/src/extra_interview_problems/glassdoor/2015/anagram.py
+++ b/src/extra_interview_problems/glassdoor/2015/anagram.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 from collections import Counter
 
diff --git a/src/extra_interview_problems/glassdoor/2015/binary_search.py b/src/extra_interview_problems/glassdoor/2015/binary_search.py
index 10d29a4..1ce26d6 100644
--- a/src/extra_interview_problems/glassdoor/2015/binary_search.py
+++ b/src/extra_interview_problems/glassdoor/2015/binary_search.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 
 def binary_search_rec(array, item, lo=0, hi = None):
diff --git a/src/extra_interview_problems/glassdoor/2015/check_if_3_numbers_sum_to_zero.py b/src/extra_interview_problems/glassdoor/2015/check_if_3_numbers_sum_to_zero.py
index fa6face..33c3e3e 100644
--- a/src/extra_interview_problems/glassdoor/2015/check_if_3_numbers_sum_to_zero.py
+++ b/src/extra_interview_problems/glassdoor/2015/check_if_3_numbers_sum_to_zero.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 ''' Determine if an Array of integers contains 3 numbers that sum to 0 '''
 
diff --git a/src/extra_interview_problems/glassdoor/2015/check_if_bst.py b/src/extra_interview_problems/glassdoor/2015/check_if_bst.py
index a6af0a6..e9da054 100644
--- a/src/extra_interview_problems/glassdoor/2015/check_if_bst.py
+++ b/src/extra_interview_problems/glassdoor/2015/check_if_bst.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 Given a tree find out whether is a BST or not
diff --git a/src/extra_interview_problems/glassdoor/2015/check_if_palindrome.py b/src/extra_interview_problems/glassdoor/2015/check_if_palindrome.py
index 85d9c44..0002cee 100644
--- a/src/extra_interview_problems/glassdoor/2015/check_if_palindrome.py
+++ b/src/extra_interview_problems/glassdoor/2015/check_if_palindrome.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 
 from collections import defaultdict
diff --git a/src/extra_interview_problems/glassdoor/2015/check_non_overlapping_intervals.py b/src/extra_interview_problems/glassdoor/2015/check_non_overlapping_intervals.py
index 9fe6bba..f8213ef 100644
--- a/src/extra_interview_problems/glassdoor/2015/check_non_overlapping_intervals.py
+++ b/src/extra_interview_problems/glassdoor/2015/check_non_overlapping_intervals.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 given an array of intervals, return max number of non-overlapping intervals
diff --git a/src/extra_interview_problems/glassdoor/2015/find_if_numbers_sum_to_k.py b/src/extra_interview_problems/glassdoor/2015/find_if_numbers_sum_to_k.py
index 80bbf93..83fa3b2 100644
--- a/src/extra_interview_problems/glassdoor/2015/find_if_numbers_sum_to_k.py
+++ b/src/extra_interview_problems/glassdoor/2015/find_if_numbers_sum_to_k.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 Given an unsorted array of numbers (that may contain repeated numbers),
diff --git a/src/extra_interview_problems/glassdoor/2015/find_longest_str_unique_chars.py b/src/extra_interview_problems/glassdoor/2015/find_longest_str_unique_chars.py
index 08a2a00..a73144e 100644
--- a/src/extra_interview_problems/glassdoor/2015/find_longest_str_unique_chars.py
+++ b/src/extra_interview_problems/glassdoor/2015/find_longest_str_unique_chars.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 given a string, find longest string with unique characters
diff --git a/src/extra_interview_problems/glassdoor/2015/find_nth_fibonacci.py b/src/extra_interview_problems/glassdoor/2015/find_nth_fibonacci.py
index 8a63ef6..fad542b 100644
--- a/src/extra_interview_problems/glassdoor/2015/find_nth_fibonacci.py
+++ b/src/extra_interview_problems/glassdoor/2015/find_nth_fibonacci.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 Write a function to find the nth Fibonacci number.
diff --git a/src/extra_interview_problems/glassdoor/2015/find_prime_factors.py b/src/extra_interview_problems/glassdoor/2015/find_prime_factors.py
index 59f22f2..c7649b8 100644
--- a/src/extra_interview_problems/glassdoor/2015/find_prime_factors.py
+++ b/src/extra_interview_problems/glassdoor/2015/find_prime_factors.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 find prime factors of a number.
diff --git a/src/extra_interview_problems/glassdoor/2015/longest_common_prefix.py b/src/extra_interview_problems/glassdoor/2015/longest_common_prefix.py
index cbcec8d..dc79efe 100644
--- a/src/extra_interview_problems/glassdoor/2015/longest_common_prefix.py
+++ b/src/extra_interview_problems/glassdoor/2015/longest_common_prefix.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 Given two strings, write a function
@@ -32,6 +35,15 @@ def lcp(s1, s2):
 
     return len(lcp)
 
+def lcppy(x):
+    '''
+    >>> lcppy([[3,2,1], [3,2,1,4,5]])
+    [3, 2, 1]
+    '''
+
+    import os
+    return os.path.commonprefix(x)
+
 if __name__ == '__main__':
     import doctest
     doctest.testmod()
diff --git a/src/extra_interview_problems/glassdoor/2015/merge_and_sort_two_arrays.py b/src/extra_interview_problems/glassdoor/2015/merge_and_sort_two_arrays.py
index 1c54ea2..e40d1f1 100644
--- a/src/extra_interview_problems/glassdoor/2015/merge_and_sort_two_arrays.py
+++ b/src/extra_interview_problems/glassdoor/2015/merge_and_sort_two_arrays.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 You have two arrays with N integers in them. Merge those arrays using a
diff --git a/src/extra_interview_problems/glassdoor/2015/permutations.py b/src/extra_interview_problems/glassdoor/2015/permutations.py
index c753457..5c5c61c 100644
--- a/src/extra_interview_problems/glassdoor/2015/permutations.py
+++ b/src/extra_interview_problems/glassdoor/2015/permutations.py
@@ -1,4 +1,6 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 ''' Generate all permutations of an alphanumeric string '''
 
diff --git a/src/extra_interview_problems/glassdoor/2015/sum_two_numbers_as_strings.py b/src/extra_interview_problems/glassdoor/2015/sum_two_numbers_as_strings.py
index 370af13..ec05a14 100644
--- a/src/extra_interview_problems/glassdoor/2015/sum_two_numbers_as_strings.py
+++ b/src/extra_interview_problems/glassdoor/2015/sum_two_numbers_as_strings.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 find the sum of two integers represented as strings,
diff --git a/src/extra_interview_problems/glassdoor/2015/transversing_bt.py b/src/extra_interview_problems/glassdoor/2015/transversing_bt.py
index ba1b915..c32d000 100644
--- a/src/extra_interview_problems/glassdoor/2015/transversing_bt.py
+++ b/src/extra_interview_problems/glassdoor/2015/transversing_bt.py
@@ -1,4 +1,6 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
 
 '''
 Reconstruct a binary tree given two sequences of node traversals,
diff --git a/src/extra_interview_problems/glassdoor/2015/trie.py b/src/extra_interview_problems/glassdoor/2015/trie.py
index 72fa541..a73c531 100644
--- a/src/extra_interview_problems/glassdoor/2015/trie.py
+++ b/src/extra_interview_problems/glassdoor/2015/trie.py
@@ -1,4 +1,7 @@
-#!/bin/python
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
 
 '''
 Implement a trie. (Write the API and code for inserting into a trie).