Memoization.ipynb

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   "source": [
    "# Memoization"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Sin memoización"
   ]
  },
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   "execution_count": 1,
   "metadata": {
    "collapsed": true
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   "source": [
    "def fib(n):\n",
    "    if n == 0 or n == 1:\n",
    "        return 1\n",
    "    return fib(n-1) + fib(n-2)"
   ]
  },
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      "14930352\n",
      "CPU times: user 5.62 s, sys: 30.4 ms, total: 5.65 s\n",
      "Wall time: 5.71 s\n"
     ]
    }
   ],
   "source": [
    "%%time\n",
    "result = fib(35)\n",
    "print(result)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Memoizado"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": true
   },
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   "source": [
    "# Casos base\n",
    "storage = dict([\n",
    "    (0, 1), \n",
    "    (1, 1)\n",
    "])\n",
    "\n",
    "def fib(n):\n",
    "    if n in storage:\n",
    "        return storage[n]\n",
    "    storage[n] = fib(n-1) + fib(n-2)\n",
    "    return storage[n]"
   ]
  },
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   "metadata": {},
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     "name": "stdout",
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     "text": [
      "14930352\n",
      "CPU times: user 601 µs, sys: 328 µs, total: 929 µs\n",
      "Wall time: 712 µs\n"
     ]
    }
   ],
   "source": [
    "%%time\n",
    "result = fib(35)\n",
    "print(result)"
   ]
  },
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   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "20365011074\n",
      "CPU times: user 861 µs, sys: 825 µs, total: 1.69 ms\n",
      "Wall time: 1.56 ms\n"
     ]
    }
   ],
   "source": [
    "%%time\n",
    "result = fib(50)\n",
    "print(result)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "573147844013817084101\n",
      "CPU times: user 509 µs, sys: 402 µs, total: 911 µs\n",
      "Wall time: 617 µs\n"
     ]
    }
   ],
   "source": [
    "%%time\n",
    "result = fib(100)\n",
    "print(result)"
   ]
  },
  {
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   "execution_count": null,
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    "collapsed": true
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