day 08 - binary search.ipynb

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   "cell_type": "markdown",
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   "source": [
    "## algorithm"
   ]
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   "execution_count": 1,
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   "source": [
    "def search(data, item):\n",
    "    left, right = 0, len(data) - 1\n",
    "    \n",
    "    while left <= right:\n",
    "        middle = (left + right) // 2\n",
    "        \n",
    "        if item < data[middle]:\n",
    "            right = middle - 1\n",
    "        elif item > data[middle]:\n",
    "            left = middle + 1\n",
    "        else:\n",
    "            return middle\n",
    "        \n",
    "    return -1"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## run"
   ]
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  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "data = [2, 3, 4, 8, 22, 23, 24, 25, 26, 28, 31, 39, 40, 43, 45, 49, 54, 58, 59, 60, 72, 73, 76, 87, 95, 97, 98]\n",
    "data = sorted(data)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "2"
      ]
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     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "search(data, 4)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "-1"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
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   ],
   "source": [
    "search(data, 74)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {
    "collapsed": false
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "-1"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "search(data, 0)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
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