{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Ticket pricing\n",
"\n",
"You've been shopping around for a holiday package deal and its time to make your choice of which deal to go with. The file [01-holidays.txt](01-holidays.txt) contains a summary of your investigations. \n",
"\n",
"It's a simple text file, with one possible holiday package per line.\n",
"\n",
"Each line has four fields, separated by spaces. They are:\n",
"* The deal ID, from the price comparison website you found it.\n",
"* The holiday price, in whole pounds.\n",
"* The location of the holiday, always a single word.\n",
"* The number of nights you'd be staying. \n",
"\n",
"For example, the data file might look like this:\n",
"\n",
"```\n",
"db61bb90 769 Morgantown 3\n",
"202c898b5f 1284 Morgantown 21\n",
"def36ffcd 1514 Giessenmestia 21\n",
"389018bd0707 1052 Estacada 21\n",
"a487c4270 782 Geoje-Si 14\n",
"6caf2584a55 724 Stonington-Island 14\n",
"199608abc5 1209 Nordkapp 21\n",
"```"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Part 1\n",
"You have a budget of £1200. How many of the holidays can you afford?\n",
"\n",
"Given the example data above, you could afford four of the holidays: the trips to Estacada, Geoje-Si and Stonnington-Island, and the three-day trip to Morgantown. \n",
"\n",
"The 21 day trip to Morgantown and the trips to Giessenmestia and Nordkapp are all too expensive."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### Solution"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"[['07ea553e', '1348', 'Zhangye-Shi', '14'],\n",
" ['02d4b258b8a', '1152', 'Estacada', '3'],\n",
" ['d29a0551504e', '1210', 'Zhangye-Shi', '7']]"
]
},
"execution_count": 1,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"holidays = []\n",
"with open('01-holidays.txt') as f:\n",
" for hol_line in f.readlines():\n",
" holidays.append(hol_line.split())\n",
" \n",
"holidays[:3]"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"66"
]
},
"execution_count": 2,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"affordable_holidays = []\n",
"for h in holidays:\n",
" if int(h[1]) <= 1200:\n",
" affordable_holidays.append(h)\n",
"\n",
"len(affordable_holidays)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### Smart-alec one-line solution"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"66"
]
},
"execution_count": 3,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"sum(1 for h in open('01-holidays.txt').readlines() if int(h.split()[1]) <= 1200)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Part 2\n",
"You don't just want _a_ holiday. You want the _best_ holiday. What is the code of the holiday which would give you the best value?\n",
"\n",
"The \"value\" of a holiday is the duration per pound. Because some destinations are better than others, you'll want to scale the value for some locations. For instance, a night in Timbuktu is worth three times as much as a holiday in Bletchley.\n",
"\n",
"Assume all holidays have a relative value of 1, apart from these destinations.\n",
"\n",
"| Destination | Score |\n",
"|-------------|-------|\n",
"| Almaty | 2.0 |\n",
"| Brorfelde | 0.9 |\n",
"| Estacada | 0.4 |\n",
"| Jayuya | 0.6 |\n",
"| Karlukovo | 2.2 |\n",
"| Morgantown | 2.9 |\n",
"| Nordkapp | 1.5 |\n",
"| Nullarbor | 2.2 |\n",
"| Puente-Laguna-Garzonkuala-Penyu | 0.4 |\n",
"| Uzupis | 0.9 |\n",
"\n",
"## Example\n",
"\n",
"Given the holiday list above, the holiday to Geoje-Si (with the standard weighting of 1) has a value of $\\frac{14}{782} = 0.0179$ nights per pound. \n",
"\n",
"The trip to Estacada looks promising, at $\\frac{21}{1052} = 0.0200$ nights per pound. Unfortunately, the weighting for Estacada is low, to the adjusted cost is $0.4 \\times \\frac{21}{1052} = 0.00798$ nights per pound.\n",
"\n",
"The best value holiday is the 21 day trip to Morgantown, with a value of $2.9 \\times \\frac{21}{1284} = 0.0474$ nights per pound. Unfortunately, it's unaffordable. \n",
"\n",
"The best value affordable holiday is the trip to Stonnington Island, with $\\frac{14}{1284} = 0.0193$ nights per pound."
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"destination_values = {'Almaty': 2.0, 'Brorfelde': 0.9, 'Estacada': 0.4, 'Jayuya': 0.6, 'Karlukovo': 2.2, \n",
" 'Morgantown': 2.9,'Nordkapp': 1.5, 'Nullarbor': 2.2, \n",
" 'Puente-Laguna-Garzonkuala-Penyu': 0.4, 'Uzupis': 0.9}"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"def value_of_destination(name):\n",
" if name in destination_values:\n",
" return destination_values[name]\n",
" else:\n",
" return 1"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"def value_of_holiday(holiday):\n",
" hid, cost, destination, duration = tuple(holiday)\n",
" value = value_of_destination(destination) * float(duration) / int(cost)\n",
" return value"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"'cb24efd90'"
]
},
"execution_count": 7,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"best_holiday = ''\n",
"best_value = 0\n",
"\n",
"for h in affordable_holidays:\n",
" if value_of_holiday(h) > best_value:\n",
" best_value = value_of_holiday(h)\n",
" best_holiday = h[0]\n",
" \n",
"best_holiday"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Smart-alec solution"
]
},
{
"cell_type": "code",
"execution_count": 8,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"'cb24efd90'"
]
},
"execution_count": 8,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"max(affordable_holidays, key=value_of_holiday)[0]"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": []
}
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