euler53.ipynb

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  11     "class Integer\n",
  12     "  def factorial\n",
  13     "    (1..self).inject(:*) || 1\n",
  14     "  end\n",
  15     "  alias :! :factorial\n",
  16     "end"
  17    ]
  18   },
  19   {
  20    "cell_type": "code",
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  26     {
  27      "data": {
  28       "text/plain": [
  29        "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]"
  30       ]
  31      },
  32      "execution_count": 2,
  33      "metadata": {},
  34      "output_type": "execute_result"
  35     }
  36    ],
  37    "source": [
  38     "(1..100).each do |n|\n",
  39     "  (1..n).each do |r|\n",
  40     "  end\n",
  41     "end"
  42    ]
  43   },
  44   {
  45    "cell_type": "code",
  46    "execution_count": 6,
  47    "metadata": {
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  51     {
  52      "data": {
  53       "text/plain": [
  54        "7"
  55       ]
  56      },
  57      "execution_count": 6,
  58      "metadata": {},
  59      "output_type": "execute_result"
  60     }
  61    ],
  62    "source": [
  63     "(1..10).to_a.product((1..10).to_a).select {|n, r| n >= r}.map {|n, r| n.! / (r.! * (n - r).!)}.select {|c| c> 100}.length"
  64    ]
  65   },
  66   {
  67    "cell_type": "code",
  68    "execution_count": 8,
  69    "metadata": {
  70     "collapsed": false
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  73     {
  74      "data": {
  75       "text/plain": [
  76        "4075"
  77       ]
  78      },
  79      "execution_count": 8,
  80      "metadata": {},
  81      "output_type": "execute_result"
  82     }
  83    ],
  84    "source": [
  85     "(1..100).to_a.product((1..100).to_a).select {|n, r| \n",
  86     "  n >= r}.map {|n, r| \n",
  87     "    n.! / (r.! * (n - r).!)}.select {|c| \n",
  88     "      c > 10 ** 6}.length"
  89    ]
  90   },
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