From b1ea49f0c8ea9358f61f1598bd8fa10c78ddaed1 Mon Sep 17 00:00:00 2001
From: Donne Martin <donne.martin@gmail.com>
Date: Thu, 30 Mar 2017 05:48:26 -0400
Subject: [PATCH] Add insert m into n challenge

---
 bit_manipulation/insert_m_into_n/__init__.py  |   0
 .../insert_m_into_n_challenge.ipynb           | 173 ++++++++++++++
 .../insert_m_into_n_solution.ipynb            | 221 ++++++++++++++++++
 .../insert_m_into_n/test_insert_m_into_n.py   |  21 ++
 4 files changed, 415 insertions(+)
 create mode 100644 bit_manipulation/insert_m_into_n/__init__.py
 create mode 100644 bit_manipulation/insert_m_into_n/insert_m_into_n_challenge.ipynb
 create mode 100644 bit_manipulation/insert_m_into_n/insert_m_into_n_solution.ipynb
 create mode 100644 bit_manipulation/insert_m_into_n/test_insert_m_into_n.py

diff --git a/bit_manipulation/insert_m_into_n/__init__.py b/bit_manipulation/insert_m_into_n/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/bit_manipulation/insert_m_into_n/insert_m_into_n_challenge.ipynb b/bit_manipulation/insert_m_into_n/insert_m_into_n_challenge.ipynb
new file mode 100644
index 0000000..6d98306
--- /dev/null
+++ b/bit_manipulation/insert_m_into_n/insert_m_into_n_challenge.ipynb
@@ -0,0 +1,173 @@
+{
+ "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: Given two 16 bit numbers, n and m, and two indices i, j, insert m into n such that m starts at bit j and ends at bit i.\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 j > i?\n",
+    "    * Yes\n",
+    "* Can we assume i through j have enough space for m?\n",
+    "    * Yes\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 an input -> Exception\n",
+    "* Negative index for i or j -> Exception\n",
+    "* General case\n",
+    "<pre>\n",
+    "i      = 2\n",
+    "j      = 6\n",
+    "n      = 0000 0100 0000 0000\n",
+    "m      = 0000 0000 0001 0011\n",
+    "result = 0000 0100 0100 1100\n",
+    "</pre>"
+   ]
+  },
+  {
+   "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 Bits(object):\n",
+    "\n",
+    "    def insert_m_into_n(self, m, n, i, j):\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_insert_m_into_n.py\n",
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "\n",
+    "class TestBit(object):\n",
+    "\n",
+    "    def test_insert_m_into_n(self):\n",
+    "        n = int('0000010000111101', base=2)\n",
+    "        m = int('0000000000010011', base=2)\n",
+    "        expected = int('0000010001001101', base=2)\n",
+    "        bits = Bits()\n",
+    "        assert_equal(bits.insert_m_into_n(m, n, i=2, j=6), expected)\n",
+    "        print('Success: test_insert_m_into_n')\n",
+    "\n",
+    "\n",
+    "def main():\n",
+    "    test = TestBit()\n",
+    "    test.test_insert_m_into_n()\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/insert_m_into_n/insert_m_into_n_solution.ipynb b/bit_manipulation/insert_m_into_n/insert_m_into_n_solution.ipynb
new file mode 100644
index 0000000..c65f66a
--- /dev/null
+++ b/bit_manipulation/insert_m_into_n/insert_m_into_n_solution.ipynb
@@ -0,0 +1,221 @@
+{
+ "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: Given two 16 bit numbers, n and m, and two indices i, j, insert m into n such that m starts at bit j and ends at bit i.\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 j > i?\n",
+    "    * Yes\n",
+    "* Can we assume i through j have enough space for m?\n",
+    "    * Yes\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 an input -> Exception\n",
+    "* Negative index for i or j -> Exception\n",
+    "* General case\n",
+    "\n",
+    "<pre>\n",
+    "i = 2, j = 6\n",
+    "                    j    i\n",
+    "n      = 0000 0100 0011 1101\n",
+    "m      = 0000 0000 0001 0011\n",
+    "result = 0000 0100 0100 1101\n",
+    "</pre>"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Algorithm\n",
+    "\n",
+    "<pre>\n",
+    "                    j    i\n",
+    "n      = 0000 0100 0011 1101\n",
+    "m      = 0000 0000 0001 0011\n",
+    "\n",
+    "lmask  = 1111 1111 1111 1111  -1\n",
+    "lmask  = 1111 1111 1000 0000  -1 << (j + 1)\n",
+    "\n",
+    "rmask  = 0000 0000 0000 0001   1\n",
+    "rmask  = 0000 0000 0000 0100   1 << i\n",
+    "rmask  = 0000 0000 0000 0011   (1 << i) -1\n",
+    "\n",
+    "mask   = 1111 1111 1000 0011   lmask | rmask\n",
+    "\n",
+    "n      = 0000 0100 0011 1101\n",
+    "mask   = 1111 1111 1000 0011   n & mask \n",
+    "--------------------------------------------------\n",
+    "n2     = 0000 0100 0000 0001\n",
+    "\n",
+    "n2     = 0000 0100 0000 0001\n",
+    "mask2  = 0000 0000 0100 1100   m << i\n",
+    "--------------------------------------------------\n",
+    "result = 0000 0100 0100 1101   n2 | mask2\n",
+    "</pre>\n",
+    "\n",
+    "Complexity:\n",
+    "* Time: O(b), where b is the number of bits\n",
+    "* Space: O(b), where b is the number of bits"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Code"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "class Bits(object):\n",
+    "\n",
+    "    def insert_m_into_n(self, m, n, i, j):\n",
+    "        if None in (m, n, i, j):\n",
+    "            raise TypeError('Argument cannot be None')\n",
+    "        if i < 0 or j < 0:\n",
+    "            raise ValueError('Index cannot be negative')\n",
+    "        left_mask = -1 << (j + 1)\n",
+    "        right_mask = (1 << i) - 1\n",
+    "        n_mask = left_mask | right_mask\n",
+    "        # Clear bits from j to i, inclusive\n",
+    "        n_cleared = n & n_mask\n",
+    "        # Shift m into place before inserting it into n\n",
+    "        m_mask = m << i\n",
+    "        return n_cleared | m_mask"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Unit Test"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Overwriting test_insert_m_into_n.py\n"
+     ]
+    }
+   ],
+   "source": [
+    "%%writefile test_insert_m_into_n.py\n",
+    "from nose.tools import assert_equal\n",
+    "\n",
+    "\n",
+    "class TestBit(object):\n",
+    "\n",
+    "    def test_insert_m_into_n(self):\n",
+    "        n = int('0000010000111101', base=2)\n",
+    "        m = int('0000000000010011', base=2)\n",
+    "        expected = int('0000010001001101', base=2)\n",
+    "        bits = Bits()\n",
+    "        assert_equal(bits.insert_m_into_n(m, n, i=2, j=6), expected)\n",
+    "        print('Success: test_insert_m_into_n')\n",
+    "\n",
+    "\n",
+    "def main():\n",
+    "    test = TestBit()\n",
+    "    test.test_insert_m_into_n()\n",
+    "\n",
+    "\n",
+    "if __name__ == '__main__':\n",
+    "    main()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Success: test_insert_m_into_n\n"
+     ]
+    }
+   ],
+   "source": [
+    "%run -i test_insert_m_into_n.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/insert_m_into_n/test_insert_m_into_n.py b/bit_manipulation/insert_m_into_n/test_insert_m_into_n.py
new file mode 100644
index 0000000..4fcc231
--- /dev/null
+++ b/bit_manipulation/insert_m_into_n/test_insert_m_into_n.py
@@ -0,0 +1,21 @@
+from nose.tools import assert_equal
+
+
+class TestBit(object):
+
+    def test_insert_m_into_n(self):
+        n = int('0000010000111101', base=2)
+        m = int('0000000000010011', base=2)
+        expected = int('0000010001001101', base=2)
+        bits = Bits()
+        assert_equal(bits.insert_m_into_n(m, n, i=2, j=6), expected)
+        print('Success: test_insert_m_into_n')
+
+
+def main():
+    test = TestBit()
+    test.test_insert_m_into_n()
+
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file