euler39.ipynb

   1 {
   2  "cells": [
   3   {
   4    "cell_type": "code",
   5    "execution_count": 13,
   6    "metadata": {
   7     "collapsed": false
   8    },
   9    "outputs": [
  10     {
  11      "data": {
  12       "text/plain": [
  13        "false"
  14       ]
  15      },
  16      "execution_count": 13,
  17      "metadata": {},
  18      "output_type": "execute_result"
  19     }
  20    ],
  21    "source": [
  22     "require 'set'"
  23    ]
  24   },
  25   {
  26    "cell_type": "code",
  27    "execution_count": 27,
  28    "metadata": {
  29     "collapsed": false
  30    },
  31    "outputs": [
  32     {
  33      "data": {
  34       "text/plain": [
  35        "1..1000"
  36       ]
  37      },
  38      "execution_count": 27,
  39      "metadata": {},
  40      "output_type": "execute_result"
  41     }
  42    ],
  43    "source": [
  44     "results = Hash.new {|x| Set.new}\n",
  45     "(1..1000).each do |p|\n",
  46     "  (1..(p/3)).each do |a|\n",
  47     "    (1..((p-a)/2)).each do |b|\n",
  48     "      c = p-(a+b)\n",
  49     "      if a ** 2 + b ** 2 == c ** 2\n",
  50     "        # puts \"p = #{p}, a, b, c: #{a} #{b} #{c}\"\n",
  51     "        results[p] = results[p].add(Set.new [a, b, c])\n",
  52     "      end\n",
  53     "    end\n",
  54     "  end\n",
  55     "end"
  56    ]
  57   },
  58   {
  59    "cell_type": "code",
  60    "execution_count": 28,
  61    "metadata": {
  62     "collapsed": false
  63    },
  64    "outputs": [
  65     {
  66      "data": {
  67       "text/plain": [
  68        "3"
  69       ]
  70      },
  71      "execution_count": 28,
  72      "metadata": {},
  73      "output_type": "execute_result"
  74     }
  75    ],
  76    "source": [
  77     "results[120].length"
  78    ]
  79   },
  80   {
  81    "cell_type": "code",
  82    "execution_count": 29,
  83    "metadata": {
  84     "collapsed": false
  85    },
  86    "outputs": [
  87     {
  88      "data": {
  89       "text/plain": [
  90        "840"
  91       ]
  92      },
  93      "execution_count": 29,
  94      "metadata": {},
  95      "output_type": "execute_result"
  96     }
  97    ],
  98    "source": [
  99     "results.keys.max_by {|p| results[p].length}"
 100    ]
 101   },
 102   {
 103    "cell_type": "code",
 104    "execution_count": null,
 105    "metadata": {
 106     "collapsed": true
 107    },
 108    "outputs": [],
 109    "source": []
 110   }
 111  ],
 112  "metadata": {
 113   "kernelspec": {
 114    "display_name": "Ruby 2.4.0",
 115    "language": "ruby",
 116    "name": "ruby"
 117   },
 118   "language_info": {
 119    "file_extension": ".rb",
 120    "mimetype": "application/x-ruby",
 121    "name": "ruby",
 122    "version": "2.4.0"
 123   }
 124  },
 125  "nbformat": 4,
 126  "nbformat_minor": 0
 127 }