Added some further ipython solutions.

This commit is contained in:
Felix Martin 2018-02-09 16:39:51 +01:00
parent 2e825d4f78
commit 60d4969eff
3 changed files with 174 additions and 13 deletions

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@ -10,31 +10,41 @@
"\n", "\n",
"$2^2=4, 2^3=8, 2^4=16, 2^5=32$\n", "$2^2=4, 2^3=8, 2^4=16, 2^5=32$\n",
"\n", "\n",
"32=9, 33=27, 34=81, 35=243\n", "$3^2=9, 3^3=27, 3^4=81, 3^5=243$\n",
"\n", "\n",
"42=16, 43=64, 44=256, 45=1024\n", "$4^2=16, 4^3=64, 4^4=256, 4^5=1024$\n",
"\n", "\n",
"52=25, 53=125, 54=625, 55=3125\n", "$5^2=25, 5^3=125, 5^4=625, 5^5=3125$\n",
"\n", "\n",
"If they are then placed in numerical order, with any repeats removed, we get the following sequence of 15 distinct terms:\n", "If they are then placed in numerical order, with any repeats removed, we get the following sequence of 15 distinct terms:\n",
"\n", "\n",
"4, 8, 9, 16, 25, 27, 32, 64, 81, 125, 243, 256, 625, 1024, 3125\n", "$4, 8, 9, 16, 25, 27, 32, 64, 81, 125, 243, 256, 625, 1024, 3125$\n",
"\n", "\n",
"How many distinct terms are in the sequence generated by ab for 2 ≤ a ≤ 100 and 2 ≤ b ≤ 100?" "How many distinct terms are in the sequence generated by $a^b$ for $2 ≤ a ≤ 100$ and $2 ≤ b ≤ 100$?"
] ]
}, },
{ {
"cell_type": "code", "cell_type": "code",
"execution_count": null, "execution_count": 1,
"metadata": { "metadata": {},
"collapsed": true "outputs": [
}, {
"outputs": [], "name": "stdout",
"source": [] "output_type": "stream",
"text": [
"9183\n"
]
}
],
"source": [
"s = len(set([a**b for a in range(2, 101) for b in range(2, 101)]))\n",
"assert(s == 9183)\n",
"print(s)"
]
} }
], ],
"metadata": { "metadata": {
"comopletion_date": "", "comopletion_date": "Fri, 25 Aug 2017, 10:03",
"kernelspec": { "kernelspec": {
"display_name": "Python 3", "display_name": "Python 3",
"language": "python", "language": "python",
@ -52,7 +62,10 @@
"pygments_lexer": "ipython3", "pygments_lexer": "ipython3",
"version": "3.6.3" "version": "3.6.3"
}, },
"tags": [] "tags": [
"distinct",
"powers"
]
}, },
"nbformat": 4, "nbformat": 4,
"nbformat_minor": 2 "nbformat_minor": 2

83
ipython/EulerProblem030.ipynb Executable file
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@ -0,0 +1,83 @@
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Euler Problem 30\n",
"\n",
"Surprisingly there are only three numbers that can be written as the sum of fourth powers of their digits:\n",
"\n",
"$1634 = 1^4 + 6^4 + 3^4 + 4^4$\n",
"\n",
"$8208 = 8^4 + 2^4 + 0^4 + 8^4$\n",
"\n",
"$9474 = 9^4 + 4^4 + 7^4 + 4^4$\n",
"\n",
"As $1 = 1^4$ is not a sum it is not included.\n",
"\n",
"The sum of these numbers is $1634 + 8208 + 9474 = 19316$.\n",
"\n",
"Find the sum of all the numbers that can be written as the sum of fifth powers of their digits."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"This is an eays brute force. We look up the fifth powers."
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"443839\n"
]
}
],
"source": [
"fifth_power_lookup = {str(i): i**5 for i in range(0,10)}\n",
"\n",
"def is_number_sum_of_fiths_powers_of_digits(n):\n",
" return n == sum([fifth_power_lookup[d] for d in str(n)])\n",
"\n",
"s = sum([i for i in range(1, 1000000) if is_number_sum_of_fiths_powers_of_digits(i) and not i is 1])\n",
"print(s)\n",
"assert(s == 443839)"
]
}
],
"metadata": {
"completion_date": "Fri, 25 Aug 2017, 12:13",
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.6.3"
},
"tags": [
"digit",
"powers",
"brute force"
]
},
"nbformat": 4,
"nbformat_minor": 2
}

65
ipython/EulerProblem031.ipynb Executable file
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@ -0,0 +1,65 @@
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Euler Problem 31\n",
"\n",
"In England the currency is made up of pound, £, and pence, p, and there are eight coins in general circulation:\n",
"\n",
"1p, 2p, 5p, 10p, 20p, 50p, £1 (100p) and £2 (200p).\n",
"\n",
"It is possible to make £2 in the following way:\n",
"\n",
"1×£1 + 1×50p + 2×20p + 1×5p + 1×2p + 3×1p\n",
"\n",
"How many different ways can £2 be made using any number of coins?"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"I really have mental issues to this in a non recursive way."
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"\n",
" "
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.6.3"
}
},
"nbformat": 4,
"nbformat_minor": 2
}