diff --git a/README.md b/README.md
index 851408c..6b3577f 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-Algos in Python
+Algorithms in Python
 ======
 
 Implementations of a few algorithms and datastructures for fun and profit!
@@ -42,6 +42,8 @@ Completed
   - String Reverse
   - Parenthesis Matching
   - Infix to Postfix
+- Modular exponentiation
+- Modular multiplicative inverse
 
 
 Tests
@@ -52,3 +54,5 @@ Tests
     python -m tests.heap_test
     python -m tests.unionfind_test
     python -m tests.singly_linked_list_test
+    python -m tests.modular_exponentiation_test
+    python -m tests.modular_multiplicative_inverse_test
diff --git a/lists/queue.py b/lists/queue.py
index a33fa83..e6883f1 100644
--- a/lists/queue.py
+++ b/lists/queue.py
@@ -1,6 +1,12 @@
+from collections import deque
+
+
 class Queue(object):
+    """Wrapper around collections.deque to provide the api consistent with
+    a Queue"""
+
     def __init__(self):
-        self.items = []
+        self.items = deque()
 
     def __str__(self):
         return ("Queue of size: %d" % len(self.items))
@@ -9,11 +15,10 @@ def isEmpty(self):
         return len(self.items) == 0
 
     def enqueue(self, item):
-        self.items.insert(0, item)
+        self.items.append(item)
 
     def dequeue(self):
-        return self.items.pop()
+        return self.items.popleft()
 
     def size(self):
         return len(self.items)
-
diff --git a/misc/__init__.py b/misc/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/misc/modular_exponentiation.py b/misc/modular_exponentiation.py
new file mode 100644
index 0000000..43c66ee
--- /dev/null
+++ b/misc/modular_exponentiation.py
@@ -0,0 +1,22 @@
+"""
+Problem: https://en.wikipedia.org/wiki/Modular_exponentiation
+"""
+
+def modular_exponentiation(base, exp, mod):
+	if exp < 1:
+		raise ValueError("Exponentiation should be ve+ int")
+	if mod == 1:
+		return 0
+	elif mod < 1:
+		raise ValueError("Modulus should be ve+ int")
+	#Initialize result to 1
+	result = 1
+	base %= mod
+	while exp > 0:
+		#multiply base to result if exp is odd
+		if exp % 2 == 1:
+			result = (result * base) % mod
+		#Double base and half exp
+		exp = exp >> 1
+		base = (base ** 2) % mod
+	return result
\ No newline at end of file
diff --git a/misc/modular_multiplicative_inverse.py b/misc/modular_multiplicative_inverse.py
new file mode 100644
index 0000000..36dd550
--- /dev/null
+++ b/misc/modular_multiplicative_inverse.py
@@ -0,0 +1,42 @@
+"""
+Problem: https://en.wikipedia.org/wiki/Modular_multiplicative_inverse
+"""
+import GCD as gcd
+
+def modular_multiplicative_inv(a, m):
+	if m == 1:
+		return 0
+	if m < 1:
+		raise ValueError('Modulus should be ve+ int > 0')
+	# check for co-prime condition
+	if gcd.greatest_common_divisor(a, m) != 1:
+		raise ValueError('a and m are not co-primes')
+
+	# Make var "a" positive if it's negative
+	if a < 0:
+		a %= m
+
+	# Initialise vars
+	m0 = m
+	x0 = 0
+	x1 = 1
+
+	while a > 1:
+		# Calculate quotient q; store m into temp t
+		q = a / m
+		t = m
+
+		# Calculate m as remainder(a, m); store temp t into a
+		m = a % m
+		a = t
+
+		# Assign x0 into temp t; Calculate x0 and store temp t into x1
+		t = x0
+		x0 = x1 - q * x0
+		x1 = t
+
+	# If x1 is negative then add modulus m0
+	if x1 < 0:
+		x1 += m0
+
+	return x1
\ No newline at end of file
diff --git a/tests/modular_exponentiation_test.py b/tests/modular_exponentiation_test.py
new file mode 100644
index 0000000..8ab9f68
--- /dev/null
+++ b/tests/modular_exponentiation_test.py
@@ -0,0 +1,16 @@
+import os, sys
+import unittest
+sys.path.append(os.path.join(os.getcwd(), os.path.pardir))
+from misc import modular_exponentiation as me
+
+class TestLCS(unittest.TestCase):
+    def test_modular_exponentiation(self):
+    	self.assertEqual(me.modular_exponentiation(2, 10, 100), 24)
+    	self.assertEqual(me.modular_exponentiation(2, 200, 10), 6)
+    	self.assertEqual(me.modular_exponentiation(5, 20, 1), 0)
+    	#self.assertEqual(me.modular_exponentiation(8, 1, 10), 8)
+    	self.assertRaises(ValueError, me.modular_exponentiation, 12, -1, 10)
+    	self.assertRaises(ValueError, me.modular_exponentiation, 12, 5, 0)
+
+if __name__ == "__main__":
+    unittest.main()
\ No newline at end of file
diff --git a/tests/modular_multiplicative_inverse_test.py b/tests/modular_multiplicative_inverse_test.py
new file mode 100644
index 0000000..165eeaf
--- /dev/null
+++ b/tests/modular_multiplicative_inverse_test.py
@@ -0,0 +1,16 @@
+import os, sys
+import unittest
+sys.path.append(os.path.join(os.getcwd(), os.path.pardir))
+from misc import modular_multiplicative_inverse as mmi
+
+class TestLCS(unittest.TestCase):
+    def test_modular_multiplicative_inverse(self):
+    	self.assertEqual(mmi.modular_multiplicative_inv(10, 7), 5)
+    	self.assertEqual(mmi.modular_multiplicative_inv(45, 13), 11)
+    	self.assertEqual(mmi.modular_multiplicative_inv(52, 1), 0)
+ 
+    	self.assertRaises(ValueError, mmi.modular_multiplicative_inv, 12, -1)
+    	self.assertRaises(ValueError, mmi.modular_multiplicative_inv, 12, 2)
+
+if __name__ == "__main__":
+    unittest.main()
\ No newline at end of file
diff --git a/trees/binarysearchtree.py b/trees/binarysearchtree.py
index 14885c0..fb573e3 100644
--- a/trees/binarysearchtree.py
+++ b/trees/binarysearchtree.py
@@ -100,13 +100,13 @@ def insert(self, value):
         else:
             node = self.root
             while node and node.value != value:
+                if node.value == value:
+                  return
                 parent = node
                 if node.value < value:
                     node = node.right
                 else:
                     node = node.left
-            if node.value == value:
-              return
             if parent.value > value:
                 parent.left = new_node
             else: