euler-001-multiples-of-3-and-5-20130731.ipynb

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 "metadata": {
  "name": "euler-001-multiples-of-3-and-5-20130731"
 },
 "nbformat": 3,
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "markdown",
     "metadata": {},
     "source": [
      "If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.  \n",
      "\n",
      "Find the sum of all the multiples of 3 or 5 below 1000."
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def foo(n):\n",
      "    total = 0\n",
      "    for i in range(n):\n",
      "        if i % 3 == 0 or i % 5 == 0:\n",
      "            total += i\n",
      "    return total"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 1
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "n = 1000\n",
      "%timeit foo(n)\n",
      "foo(n)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1000 loops, best of 3: 282 us per loop\n"
       ]
      },
      {
       "output_type": "pyout",
       "prompt_number": 2,
       "text": [
        "233168"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def foo(n):\n",
      "    total = 0\n",
      "    for i in range(n):\n",
      "        if i % 3 == 0:\n",
      "            total += i\n",
      "        if i % 5 == 0:\n",
      "            total += i\n",
      "    return total"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 3
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "n = 1000\n",
      "%timeit foo(n)\n",
      "foo(n)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1000 loops, best of 3: 319 us per loop\n"
       ]
      },
      {
       "output_type": "pyout",
       "prompt_number": 4,
       "text": [
        "266333"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "def foo(n):\n",
      "    return sum(filter((lambda x: x % 3 == 0 or x % 5 == 0), range(n)))"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [],
     "prompt_number": 5
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "n = 1000\n",
      "%timeit foo(n)\n",
      "foo(n)"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "1000 loops, best of 3: 384 us per loop\n"
       ]
      },
      {
       "output_type": "pyout",
       "prompt_number": 6,
       "text": [
        "233168"
       ]
      }
     ],
     "prompt_number": 6
    }
   ],
   "metadata": {}
  }
 ]
}