二分探索

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 "worksheets": [
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   "cells": [
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     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "#\u4e8c\u5206\u63a2\u7d22"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def bi_search(n):\n",
      "    low, high = 0, n\n",
      "    while high - low > 1e-8:\n",
      "        x = (low + high) / 2\n",
      "        if x**2 < n:\n",
      "            low = x\n",
      "        else:\n",
      "            high = x\n",
      "    return (low + high) / 2"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 12
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "%time bi_search(2)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Wall time: 0 ns\n"
       ]
      },
      {
       "metadata": {},
       "output_type": "pyout",
       "prompt_number": 13,
       "text": [
        "1.414213564246893"
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     "prompt_number": 13
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http://nbviewer.ipython.org/gist/Tsutomu-KKE/ccd3687577cd72a5213f