julia_menu_problem.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Menu exercise in Julia"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Requests package"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 66,
   "metadata": {
    "collapsed": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "\"\\$15.05\\nmixed fruit,\\$2.15\\nfrench fries,\\$2.75\\nside salad,\\$3.35\\nhot wings,\\$3.55\\nmozzarella sticks,\\$4.20\\nsampler plate,\\$5.80\\n\""
      ]
     },
     "execution_count": 66,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# Pkg.add(\"Requests\")\n",
    "using Requests\n",
    "import Requests: get, post, put, delete, options\n",
    "menu_url = \"https://gist.github.com/yoon/2cc42ef2e9ecfa9ec13b\"\n",
    "menu = readall(get(menu_url))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Importing menu"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 61,
   "metadata": {
    "collapsed": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "(1505,Dict{Any,Any}(\"mixed fruit\"=>215,\"side salad\"=>335,\"french fries\"=>275,\"mozzarella sticks\"=>420,\"sampler plate\"=>580,\"hot wings\"=>355))"
      ]
     },
     "execution_count": 61,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "lines = split(menu, \"\\n\")\n",
    "target_price = round(Int, parse(Float64, match(r\"\\d+\\.\\d{2}\", shift!(lines)).match) * 100)\n",
    "menu_items = Dict()\n",
    "for line in lines\n",
    "    splits = split(line, \",\")\n",
    "    price = match(r\"\\d+\\.\\d{2}\", pop!(splits))\n",
    "    item = join(splits)\n",
    "    if sizeof(price) > 0 && sizeof(item) > 0\n",
    "        menu_items[item] = round(Int, parse(Float64, string(price.match)) * 100)\n",
    "    end\n",
    "end\n",
    "target_price, menu_items"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Solutions functions"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 62,
   "metadata": {
    "collapsed": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "solutions (generic function with 1 method)"
      ]
     },
     "execution_count": 62,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "function solutions(target, items)\n",
    "  items_within = within(target, items)\n",
    "  combinations = []\n",
    "  for (k,v) in items_within\n",
    "    if target == v\n",
    "      push!(combinations, Dict(k => v))\n",
    "    else\n",
    "      for combination in solutions(target - v, items_within)\n",
    "        push!(combinations, cat(1, [Dict(k => v)], combination))\n",
    "      end\n",
    "    end\n",
    "  end\n",
    "  combinations\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 63,
   "metadata": {
    "collapsed": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "within (generic function with 1 method)"
      ]
     },
     "execution_count": 63,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "function within(target,items)\n",
    "  filter((k,v) -> v <= target, items)\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 64,
   "metadata": {
    "collapsed": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "13-element Array{Any,1}:\n",
       " [Dict(\"mixed fruit\"=>215),Dict(\"mixed fruit\"=>215),Dict(\"mixed fruit\"=>215),Dict(\"mixed fruit\"=>215),Dict(\"mixed fruit\"=>215),Dict(\"mixed fruit\"=>215),Dict(\"mixed fruit\"=>215)]\n",
       " [Dict(\"mixed fruit\"=>215),Dict(\"sampler plate\"=>580),Dict(\"hot wings\"=>355),Dict(\"hot wings\"=>355)]                                                                             \n",
       " [Dict(\"mixed fruit\"=>215),Dict(\"hot wings\"=>355),Dict(\"sampler plate\"=>580),Dict(\"hot wings\"=>355)]                                                                             \n",
       " [Dict(\"mixed fruit\"=>215),Dict(\"hot wings\"=>355),Dict(\"hot wings\"=>355),Dict(\"sampler plate\"=>580)]                                                                             \n",
       " [Dict(\"sampler plate\"=>580),Dict(\"mixed fruit\"=>215),Dict(\"hot wings\"=>355),Dict(\"hot wings\"=>355)]                                                                             \n",
       " [Dict(\"sampler plate\"=>580),Dict(\"hot wings\"=>355),Dict(\"mixed fruit\"=>215),Dict(\"hot wings\"=>355)]                                                                             \n",
       " [Dict(\"sampler plate\"=>580),Dict(\"hot wings\"=>355),Dict(\"hot wings\"=>355),Dict(\"mixed fruit\"=>215)]                                                                             \n",
       " [Dict(\"hot wings\"=>355),Dict(\"mixed fruit\"=>215),Dict(\"sampler plate\"=>580),Dict(\"hot wings\"=>355)]                                                                             \n",
       " [Dict(\"hot wings\"=>355),Dict(\"mixed fruit\"=>215),Dict(\"hot wings\"=>355),Dict(\"sampler plate\"=>580)]                                                                             \n",
       " [Dict(\"hot wings\"=>355),Dict(\"sampler plate\"=>580),Dict(\"mixed fruit\"=>215),Dict(\"hot wings\"=>355)]                                                                             \n",
       " [Dict(\"hot wings\"=>355),Dict(\"sampler plate\"=>580),Dict(\"hot wings\"=>355),Dict(\"mixed fruit\"=>215)]                                                                             \n",
       " [Dict(\"hot wings\"=>355),Dict(\"hot wings\"=>355),Dict(\"mixed fruit\"=>215),Dict(\"sampler plate\"=>580)]                                                                             \n",
       " [Dict(\"hot wings\"=>355),Dict(\"hot wings\"=>355),Dict(\"sampler plate\"=>580),Dict(\"mixed fruit\"=>215)]                                                                             "
      ]
     },
     "execution_count": 64,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "solutions(target_price, menu_items)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {
    "collapsed": false
   },
   "source": [
    "## References\n",
    "* http://www.juliabox.org/\n",
    "* http://learnxinyminutes.com/docs/julia/\n",
    "* http://en.wikibooks.org/wiki/Introducing_Julia\n",
    "* http://docs.julialang.org/en/release-0.4/\n",
    "* http://pkg.julialang.org/"
   ]
  }
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