euler48.ipynb

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  10     {
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  12       "text/plain": [
  13        ":modular_exponent"
  14       ]
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  21    "source": [
  22     "# Calculate ( n ** e ) mod b\n",
  23     "def modular_exponent(n, e, b)\n",
  24     "  e_prime = 1\n",
  25     "  c = n % b\n",
  26     "  while e_prime < e\n",
  27     "    c = (c * n) % b\n",
  28     "    e_prime += 1\n",
  29     "  end\n",
  30     "  c\n",
  31     "end"
  32    ]
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  43       "text/plain": [
  44        "4"
  45       ]
  46      },
  47      "execution_count": 6,
  48      "metadata": {},
  49      "output_type": "execute_result"
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  51    ],
  52    "source": [
  53     "modular_exponent 4, 3, 10"
  54    ]
  55   },
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  58    "execution_count": 7,
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  66        ":self_powers"
  67       ]
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  69      "execution_count": 7,
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  74    "source": [
  75     "def self_powers(n_max, b)\n",
  76     "  (1..n_max).map {|n| modular_exponent n, n, b}.sum % b\n",
  77     "end"
  78    ]
  79   },
  80   {
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  82    "execution_count": 10,
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  90        "10405071317"
  91       ]
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  93      "execution_count": 10,
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  98    "source": [
  99     "self_powers 10, 1000000000000"
 100    ]
 101   },
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 112        "9110846700"
 113       ]
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 115      "execution_count": 11,
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 120    "source": [
 121     "self_powers 1000, 10**10"
 122    ]
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