MAGIC NUMBER 10103

prime.ipynb

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    "def primes(n):\n",
    "    sieve = [True] * n\n",
    "    for i in range(3,int(n**0.5)+1,2):\n",
    "        if sieve[i]:\n",
    "            sieve[i*i::2*i]=[False]*((n-i*i-1)//(2*i)+1)\n",
    "    return [2] + [i for i in range(3,n,2) if sieve[i]]"
   ]
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  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {},
   "outputs": [],
   "source": [
    "p = primes(10000000)\n",
    "ps = [n for n in p if n > 1000]\n",
    "notps = [n for n in range(2, 1000) if not n in p]"
   ]
  },
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   "cell_type": "code",
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   "metadata": {},
   "outputs": [
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     "name": "stdout",
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     "text": [
      "no..\n"
     ]
    }
   ],
   "source": [
    "# 모든 합성수들에 대해서 결과값이 1이 아닌 소수를 찾는 코드.\n",
    "for prime in ps:\n",
    "    for notp in notps:\n",
    "        if prime ** ~-notp % notp == 1:\n",
    "            break\n",
    "    else:\n",
    "        print(prime)\n",
    "        break\n",
    "else:\n",
    "    print('no..')"
   ]
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   "cell_type": "code",
   "execution_count": 20,
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     "name": "stdout",
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     "text": [
      "561\n",
      "645\n",
      "946\n"
     ]
    }
   ],
   "source": [
    "# 10103 이 안되는 케이스들을 골라보자\n",
    "for notp in notps:\n",
    "    if 10103 ** ~-notp % notp == 1:\n",
    "        print(notp)"
   ]
  },
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   "cell_type": "code",
   "execution_count": null,
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