{
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"data": {
"text/html": [
"\n"
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""
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"source": [
"%%HTML\n",
""
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"source": [
"def eucld_gcd(a, b):\n",
" \"\"\"\n",
" Computes the greatest common divisor (GCD) of \n",
" two integers using the Euclidean algorithm.\n",
"\n",
" Parameters:\n",
" a (int): The first integer.\n",
" b (int): The second integer.\n",
"\n",
" Returns:\n",
" int: The greatest common divisor of a and b.\n",
" \"\"\"\n",
" if a < b:\n",
" a, b = b, a\n",
" if b == 0:\n",
" return a\n",
" r = a % b\n",
" if r == 0:\n",
" return b\n",
" return eucld_gcd(b, r)\n",
"\n",
"\n",
"eucld_gcd(252, 105)"
]
},
{
"cell_type": "code",
"execution_count": 6,
"id": "c060ee17",
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"[1, -48]"
]
},
"execution_count": 6,
"metadata": {},
"output_type": "execute_result"
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"source": [
"import numpy as np\n",
"\n",
"\n",
"def ext_eucld(a, b):\n",
" \"\"\"\n",
" Computes the extended Euclidean algorithm to find the \n",
" greatest common divisor (GCD)of two integers, and \n",
" also the coefficients (x, y) of the equation:\n",
" a*x + b*y = GCD(a, b)\n",
"\n",
" This method returns the coefficients (x, y) \n",
" such that a*x + b*y = GCD(a, b).\n",
"\n",
" Parameters:\n",
" a (int): The first integer.\n",
" b (int): The second integer.\n",
"\n",
" Returns:\n",
" list: A list of two integers [x, y] where x and y are the \n",
" coefficients for the linear combination of a and b \n",
" that equals their GCD.\n",
" \"\"\"\n",
" swap = False\n",
" if a < b:\n",
" a, b = b, a\n",
" swap = True\n",
"\n",
" def eucld(a, b):\n",
" if b in {0,1}:\n",
" return []\n",
" ls = []\n",
" while b != 1:\n",
" r = a % b\n",
" if r == 0:\n",
" return ls\n",
" idx = (a - r) // b\n",
" ls.append(idx)\n",
" a = b\n",
" b = r\n",
" return ls\n",
"\n",
" row = np.array([[1, 0], [0, 1]])\n",
" ls = eucld(a, b)\n",
" for i in ls:\n",
" row = np.append(row, [row[-2] - i * row[-1]], axis=0)\n",
"\n",
" if swap:\n",
" return list(row[-1])[::-1]\n",
"\n",
" return list(row[-1])\n",
"\n",
"\n",
"ext_eucld(97, 2)"
]
},
{
"cell_type": "code",
"execution_count": 7,
"id": "d3edd1f6",
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"a=5, b=7, gcd=1, m=3, n=-2, ma+nb=1\n"
]
}
],
"source": [
<<<<<<< HEAD
"a, b= 5, 7\n",
=======
"a = 5\n",
"b = 7\n",
>>>>>>> ffbe3bbd8623bff453d16b942b7cf035c20d808c
"gcd = eucld_gcd(a, b)\n",
"m, n = ext_eucld(a, b)\n",
"print(f\"a={a}, b={b}, gcd={gcd}, m={m}, n={n}, ma+nb={m*a+n*b}\")"
]
},
{
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"execution_count": null,
"id": "782bb8d3",
"metadata": {},
"outputs": [],
"source": []
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{
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"execution_count": null,
"id": "e224063e",
"metadata": {},
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"source": []
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{
"cell_type": "code",
"execution_count": null,
"id": "3da0aaac-23b4-4118-ae3e-aef611f0f38c",
"metadata": {},
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"source": []
}
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