diff --git a/bit_manipulation/bit/__init__.py b/bit_manipulation/bit/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/bit_manipulation/bit/bit_challenge.ipynb b/bit_manipulation/bit/bit_challenge.ipynb
new file mode 100644
index 0000000..85fc5ae
--- /dev/null
+++ b/bit_manipulation/bit/bit_challenge.ipynb
@@ -0,0 +1,225 @@
+{
+ "cells": [
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)."
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "# Challenge Notebook"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Problem: Implement common bit manipulation operations: get_bit, set_bit, clear_bit, clear_bits_msb_to_index, clear_bits_msb_to_lsb, update_bit.\n",
+ "\n",
+ "* [Constraints](#Constraints)\n",
+ "* [Test Cases](#Test-Cases)\n",
+ "* [Algorithm](#Algorithm)\n",
+ "* [Code](#Code)\n",
+ "* [Unit Test](#Unit-Test)\n",
+ "* [Solution Notebook](#Solution-Notebook)"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Constraints\n",
+ "\n",
+ "* Can we assume the inputs are valid?\n",
+ " * No\n",
+ "* Can we assume this fits memory?\n",
+ " * Yes"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Test Cases\n",
+ "\n",
+ "* None as a number input -> Exception\n",
+ "* Negative index -> Exception\n",
+ "\n",
+ "### get_bit\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = True\n",
+ "### set_bit\n",
+ " number = 0b10001110, index = 4\n",
+ " expected = 0b10011110\n",
+ "### clear_bit\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = 0b10000110\n",
+ "### clear_bits_msb_to_index\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = 0b00000110\n",
+ "### clear_bits_index_to_lsb\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = 0b10000000\n",
+ "### update_bit\n",
+ " number = 0b10001110, index = 3, value = 1\n",
+ " expected = 0b10001110\n",
+ " number = 0b10001110, index = 3, value = 0\n",
+ " expected = 0b10000110\n",
+ " number = 0b10001110, index = 0, value = 1\n",
+ " expected = 0b10001111"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Algorithm\n",
+ "\n",
+ "Refer to the [Solution Notebook](). If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start."
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Code"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": null,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [],
+ "source": [
+ "class Bit(object):\n",
+ "\n",
+ " def __init__(self, number):\n",
+ " # TODO: Implement me\n",
+ " pass\n",
+ "\n",
+ " def get_bit(self, index):\n",
+ " # TODO: Implement me\n",
+ " pass\n",
+ "\n",
+ " def set_bit(self, index):\n",
+ " # TODO: Implement me\n",
+ " pass\n",
+ "\n",
+ " def clear_bit(self, index):\n",
+ " # TODO: Implement me\n",
+ " pass\n",
+ "\n",
+ " def clear_bits_msb_to_index(self, index):\n",
+ " # TODO: Implement me\n",
+ " pass\n",
+ "\n",
+ " def clear_bits_index_to_lsb(self, index):\n",
+ " # TODO: Implement me\n",
+ " pass\n",
+ "\n",
+ " def update_bit(self, index, value):\n",
+ " # TODO: Implement me\n",
+ " pass"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Unit Test"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "**The following unit test is expected to fail until you solve the challenge.**"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": null,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [],
+ "source": [
+ "# %load test_bit.py\n",
+ "from nose.tools import assert_equal\n",
+ "\n",
+ "\n",
+ "class TestBit(object):\n",
+ "\n",
+ " def test_bit(self):\n",
+ " number = int('10001110', base=2)\n",
+ " bit = Bit(number)\n",
+ " assert_equal(bit.get_bit(index=3), True)\n",
+ " expected = int('10011110', base=2)\n",
+ " assert_equal(bit.set_bit(index=4), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10000110', base=2)\n",
+ " assert_equal(bit.clear_bit(index=3), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('00000110', base=2)\n",
+ " assert_equal(bit.clear_bits_msb_to_index(index=3), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10000000', base=2)\n",
+ " assert_equal(bit.clear_bits_index_to_lsb(index=3), expected)\n",
+ " bit = Bit(number)\n",
+ " assert_equal(bit.update_bit(index=3, value=1), number)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10000110', base=2)\n",
+ " assert_equal(bit.update_bit(index=3, value=0), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10001111', base=2)\n",
+ " assert_equal(bit.update_bit(index=0, value=1), expected)\n",
+ " print('Success: test_bit')\n",
+ "\n",
+ "\n",
+ "def main():\n",
+ " test = TestBit()\n",
+ " test.test_bit()\n",
+ "\n",
+ "\n",
+ "if __name__ == '__main__':\n",
+ " main()"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Solution Notebook\n",
+ "\n",
+ "Review the [Solution Notebook]() for a discussion on algorithms and code solutions."
+ ]
+ }
+ ],
+ "metadata": {
+ "kernelspec": {
+ "display_name": "Python 3",
+ "language": "python",
+ "name": "python3"
+ },
+ "language_info": {
+ "codemirror_mode": {
+ "name": "ipython",
+ "version": 3
+ },
+ "file_extension": ".py",
+ "mimetype": "text/x-python",
+ "name": "python",
+ "nbconvert_exporter": "python",
+ "pygments_lexer": "ipython3",
+ "version": "3.5.0"
+ }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/bit_manipulation/bit/bit_solution.ipynb b/bit_manipulation/bit/bit_solution.ipynb
new file mode 100644
index 0000000..be72758
--- /dev/null
+++ b/bit_manipulation/bit/bit_solution.ipynb
@@ -0,0 +1,358 @@
+{
+ "cells": [
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges)."
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "# Solution Notebook"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Problem: Implement common bit manipulation operations: get_bit, set_bit, clear_bit, clear_bits_msb_to_index, clear_bits_msb_to_lsb, update_bit.\n",
+ "\n",
+ "* [Constraints](#Constraints)\n",
+ "* [Test Cases](#Test-Cases)\n",
+ "* [Algorithm](#Algorithm)\n",
+ "* [Code](#Code)\n",
+ "* [Unit Test](#Unit-Test)"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Constraints\n",
+ "\n",
+ "* Can we assume the inputs are valid?\n",
+ " * No\n",
+ "* Can we assume this fits memory?\n",
+ " * Yes"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Test Cases\n",
+ "\n",
+ "* None as a number input -> Exception\n",
+ "* Negative index -> Exception\n",
+ "\n",
+ "### get_bit\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = True\n",
+ "### set_bit\n",
+ " number = 0b10001110, index = 4\n",
+ " expected = 0b10011110\n",
+ "### clear_bit\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = 0b10000110\n",
+ "### clear_bits_msb_to_index\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = 0b00000110\n",
+ "### clear_bits_index_to_lsb\n",
+ " number = 0b10001110, index = 3\n",
+ " expected = 0b10000000\n",
+ "### update_bit\n",
+ " number = 0b10001110, index = 3, value = 1\n",
+ " expected = 0b10001110\n",
+ " number = 0b10001110, index = 3, value = 0\n",
+ " expected = 0b10000110\n",
+ " number = 0b10001110, index = 0, value = 1\n",
+ " expected = 0b10001111"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Algorithm\n",
+ "\n",
+ "### get_bit\n",
+ "\n",
+ "\n",
+ "indices 7 6 5 4 3 2 1 0 index = 3\n",
+ "--------------------------------------------------\n",
+ "input 1 0 0 0 1 1 1 0 0b10001110\n",
+ "mask 0 0 0 0 1 0 0 0 1 << index\n",
+ "--------------------------------------------------\n",
+ "result 0 0 0 0 1 0 0 0 number & mask != 0\n",
+ "
\n",
+ "\n",
+ "Complexity:\n",
+ "* Time: O(n)\n",
+ "* Space: O(n)\n",
+ "\n",
+ "### set_bit\n",
+ "\n",
+ "\n",
+ "indices 7 6 5 4 3 2 1 0 index = 4\n",
+ "--------------------------------------------------\n",
+ "input 1 0 0 0 1 1 1 0 0b10001110\n",
+ "mask 0 0 0 1 0 0 0 0 1 << index\n",
+ "--------------------------------------------------\n",
+ "result 1 0 0 1 1 1 1 0 number | mask\n",
+ "
\n",
+ "\n",
+ "Complexity:\n",
+ "* Time: O(n)\n",
+ "* Space: O(n)\n",
+ "\n",
+ "### clear_bit\n",
+ "\n",
+ "\n",
+ "indices 7 6 5 4 3 2 1 0 index = 3\n",
+ "--------------------------------------------------\n",
+ "input 1 0 0 0 1 1 1 0 0b10001110\n",
+ "mask 0 0 0 0 1 0 0 0 1 << index\n",
+ "mask 1 1 1 1 0 1 1 1 ~(1 << index)\n",
+ "--------------------------------------------------\n",
+ "result 1 0 0 0 0 1 1 0 number & mask\n",
+ "
\n",
+ "\n",
+ "Complexity:\n",
+ "* Time: O(n)\n",
+ "* Space: O(n)\n",
+ "\n",
+ "### clear_bits_msb_to_index\n",
+ "\n",
+ "\n",
+ "indices 7 6 5 4 3 2 1 0 index = 3\n",
+ "--------------------------------------------------\n",
+ "input 1 0 0 0 1 1 1 0 0b10001110\n",
+ "mask 0 0 0 0 1 0 0 0 1 << index\n",
+ "mask 0 0 0 0 0 1 1 1 (1 << index) - 1\n",
+ "--------------------------------------------------\n",
+ "result 0 0 0 0 0 1 1 1 number & mask\n",
+ "
\n",
+ "\n",
+ "Complexity:\n",
+ "* Time: O(n)\n",
+ "* Space: O(n)\n",
+ "\n",
+ "### clear_bits_index_to_lsb\n",
+ "\n",
+ "\n",
+ "indices 7 6 5 4 3 2 1 0 index = 3\n",
+ "--------------------------------------------------\n",
+ "input 1 0 0 0 1 1 1 0 0b10001110\n",
+ "mask 0 0 0 1 0 0 0 0 1 << index + 1\n",
+ "mask 0 0 0 0 1 1 1 1 (1 << index + 1) - 1\n",
+ "mask 1 1 1 1 0 0 0 0 ~((1 << index + 1) - 1)\n",
+ "--------------------------------------------------\n",
+ "result 1 0 0 0 0 0 0 0 number & mask\n",
+ "
\n",
+ "\n",
+ "Complexity:\n",
+ "* Time: O(n)\n",
+ "* Space: O(n)\n",
+ "\n",
+ "### update_bit\n",
+ "\n",
+ "* Use `get_bit` to see if the value is already set or cleared\n",
+ "* If not, use `set_bit` if setting the value or `clear_bit` if clearing the value\n",
+ "\n",
+ "Complexity:\n",
+ "* Time: O(n)\n",
+ "* Space: O(n)\n",
+ "\n",
+ "\n"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Code"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 1,
+ "metadata": {
+ "collapsed": true
+ },
+ "outputs": [],
+ "source": [
+ "def validate_index(func):\n",
+ " def validate_index_wrapper(self, *args, **kwargs):\n",
+ " for arg in args:\n",
+ " if arg < 0:\n",
+ " raise IndexError('Invalid index')\n",
+ " return func(self, *args, **kwargs)\n",
+ " return validate_index_wrapper"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 2,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [],
+ "source": [
+ "class Bit(object):\n",
+ "\n",
+ " def __init__(self, number):\n",
+ " if number is None:\n",
+ " raise TypeError('number cannot be None')\n",
+ " self.number = number\n",
+ "\n",
+ " @validate_index\n",
+ " def get_bit(self, index):\n",
+ " mask = 1 << index\n",
+ " return self.number & mask != 0\n",
+ "\n",
+ " @validate_index\n",
+ " def set_bit(self, index):\n",
+ " mask = 1 << index\n",
+ " self.number |= mask\n",
+ " return self.number\n",
+ "\n",
+ " @validate_index\n",
+ " def clear_bit(self, index):\n",
+ " mask = ~(1 << index)\n",
+ " self.number &= mask\n",
+ " return self.number\n",
+ "\n",
+ " @validate_index\n",
+ " def clear_bits_msb_to_index(self, index):\n",
+ " mask = (1 << index) - 1\n",
+ " self.number &= mask\n",
+ " return self.number\n",
+ "\n",
+ " @validate_index\n",
+ " def clear_bits_index_to_lsb(self, index):\n",
+ " mask = ~((1 << index + 1) - 1)\n",
+ " self.number &= mask\n",
+ " return self.number\n",
+ "\n",
+ " @validate_index\n",
+ " def update_bit(self, index, value):\n",
+ " if value is None or value not in (0, 1):\n",
+ " raise Exception('Invalid value')\n",
+ " if self.get_bit(index) == value:\n",
+ " return self.number\n",
+ " if value:\n",
+ " self.set_bit(index)\n",
+ " else:\n",
+ " self.clear_bit(index)\n",
+ " return self.number"
+ ]
+ },
+ {
+ "cell_type": "markdown",
+ "metadata": {},
+ "source": [
+ "## Unit Test"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 3,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "Overwriting test_bit.py\n"
+ ]
+ }
+ ],
+ "source": [
+ "%%writefile test_bit.py\n",
+ "from nose.tools import assert_equal\n",
+ "\n",
+ "\n",
+ "class TestBit(object):\n",
+ "\n",
+ " def test_bit(self):\n",
+ " number = int('10001110', base=2)\n",
+ " bit = Bit(number)\n",
+ " assert_equal(bit.get_bit(index=3), True)\n",
+ " expected = int('10011110', base=2)\n",
+ " assert_equal(bit.set_bit(index=4), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10000110', base=2)\n",
+ " assert_equal(bit.clear_bit(index=3), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('00000110', base=2)\n",
+ " assert_equal(bit.clear_bits_msb_to_index(index=3), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10000000', base=2)\n",
+ " assert_equal(bit.clear_bits_index_to_lsb(index=3), expected)\n",
+ " bit = Bit(number)\n",
+ " assert_equal(bit.update_bit(index=3, value=1), number)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10000110', base=2)\n",
+ " assert_equal(bit.update_bit(index=3, value=0), expected)\n",
+ " bit = Bit(number)\n",
+ " expected = int('10001111', base=2)\n",
+ " assert_equal(bit.update_bit(index=0, value=1), expected)\n",
+ " print('Success: test_bit')\n",
+ "\n",
+ "\n",
+ "def main():\n",
+ " test = TestBit()\n",
+ " test.test_bit()\n",
+ "\n",
+ "\n",
+ "if __name__ == '__main__':\n",
+ " main()"
+ ]
+ },
+ {
+ "cell_type": "code",
+ "execution_count": 4,
+ "metadata": {
+ "collapsed": false
+ },
+ "outputs": [
+ {
+ "name": "stdout",
+ "output_type": "stream",
+ "text": [
+ "Success: test_bit\n"
+ ]
+ }
+ ],
+ "source": [
+ "%run -i test_bit.py"
+ ]
+ }
+ ],
+ "metadata": {
+ "kernelspec": {
+ "display_name": "Python 3",
+ "language": "python",
+ "name": "python3"
+ },
+ "language_info": {
+ "codemirror_mode": {
+ "name": "ipython",
+ "version": 3
+ },
+ "file_extension": ".py",
+ "mimetype": "text/x-python",
+ "name": "python",
+ "nbconvert_exporter": "python",
+ "pygments_lexer": "ipython3",
+ "version": "3.5.0"
+ }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}
diff --git a/bit_manipulation/bit/test_bit.py b/bit_manipulation/bit/test_bit.py
new file mode 100644
index 0000000..2bca822
--- /dev/null
+++ b/bit_manipulation/bit/test_bit.py
@@ -0,0 +1,38 @@
+from nose.tools import assert_equal
+
+
+class TestBit(object):
+
+ def test_bit(self):
+ number = int('10001110', base=2)
+ bit = Bit(number)
+ assert_equal(bit.get_bit(index=3), True)
+ expected = int('10011110', base=2)
+ assert_equal(bit.set_bit(index=4), expected)
+ bit = Bit(number)
+ expected = int('10000110', base=2)
+ assert_equal(bit.clear_bit(index=3), expected)
+ bit = Bit(number)
+ expected = int('00000110', base=2)
+ assert_equal(bit.clear_bits_msb_to_index(index=3), expected)
+ bit = Bit(number)
+ expected = int('10000000', base=2)
+ assert_equal(bit.clear_bits_index_to_lsb(index=3), expected)
+ bit = Bit(number)
+ assert_equal(bit.update_bit(index=3, value=1), number)
+ bit = Bit(number)
+ expected = int('10000110', base=2)
+ assert_equal(bit.update_bit(index=3, value=0), expected)
+ bit = Bit(number)
+ expected = int('10001111', base=2)
+ assert_equal(bit.update_bit(index=0, value=1), expected)
+ print('Success: test_bit')
+
+
+def main():
+ test = TestBit()
+ test.test_bit()
+
+
+if __name__ == '__main__':
+ main()
\ No newline at end of file