Project Euler Q10 - LO Man Hei

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    "### Q10\n",
    "Find the sum of all the primes below two million."
   ]
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    "def prime_numbers(n,max_len=False):\n",
    "    result = []\n",
    "    if max_len:\n",
    "        n = max_len**2//5000 + max_len*20\n",
    "    sieve = [True] * (n+1)\n",
    "    for p in range(2, n+1):\n",
    "        if (sieve[p]):\n",
    "            result.append(p)\n",
    "            if max_len and len(result) >= max_len:\n",
    "                return result\n",
    "            for i in range(p, n+1, p):\n",
    "                sieve[i] = False\n",
    "    return result\n"
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      "CPU times: user 177 ms, sys: 11.2 ms, total: 188 ms\n",
      "Wall time: 185 ms\n"
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   "source": [
    "%%time\n",
    "sum(prime_numbers(2000000))"
   ]
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   "execution_count": null,
   "id": "4ecc82cf-380d-47e7-a978-c5de24585719",
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