X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=src%2Ftask1%2Ftask1.ipynb;h=a9c4dcf5e901783c87060231f1e91a86c77053ee;hb=56de4596adb43e9505c41fdd734954099d2f8a99;hp=61839d09131ddc34e049cd6b386f997b054226c2;hpb=2332d583ac8c5c998732c629cbb16f92b750ab1c;p=summerofcode2018soln.git

diff --git a/src/task1/task1.ipynb b/src/task1/task1.ipynb
index 61839d0..a9c4dcf 100644
--- a/src/task1/task1.ipynb
+++ b/src/task1/task1.ipynb
@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 1,
+   "execution_count": 20,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -13,12 +13,13 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Part 1"
+    "# Part 1\n",
+    "`startswith()` isn't useful that often, but it makes for easily readable code when it is."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 3,
+   "execution_count": 31,
    "metadata": {},
    "outputs": [
     {
@@ -27,7 +28,40 @@
        "1136"
       ]
      },
-     "execution_count": 3,
+     "execution_count": 31,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "non_comments = 0\n",
+    "for i in instructions:\n",
+    "    if not i.startswith('#'):\n",
+    "        non_comments += 1\n",
+    "non_comments"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "This sort if simple walking along a list is sometimes easier with a list comprehension. \n",
+    "\n",
+    "In this case, I transform each element into the number 1, but only if it's not a comment. Then I sum all the 1s, which is the number of non-comment lines."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 21,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "1136"
+      ]
+     },
+     "execution_count": 21,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -45,7 +79,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 22,
    "metadata": {},
    "outputs": [
     {
@@ -54,7 +88,7 @@
        "1136"
       ]
      },
-     "execution_count": 4,
+     "execution_count": 22,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -63,9 +97,16 @@
     "sum(1 for i in open('../../data/01-mowmaster.txt') if not i.startswith('#'))"
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "How many comments and total lines?"
+   ]
+  },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 23,
    "metadata": {},
    "outputs": [
     {
@@ -74,7 +115,7 @@
        "395"
       ]
      },
-     "execution_count": 5,
+     "execution_count": 23,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -85,7 +126,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 6,
+   "execution_count": 24,
    "metadata": {},
    "outputs": [
     {
@@ -94,7 +135,7 @@
        "1531"
       ]
      },
-     "execution_count": 6,
+     "execution_count": 24,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -107,12 +148,84 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Part 2"
+    "# Part 2\n",
+    "\n",
+    "I have the `mower` as an \"object\" storing its state. (In this case, the mower is a `dict` and the state is just its location and direction.) As each instruction is executed, the mower is updated."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "An initial mower. I adopt the Scratch convention that a heading of 0 degrees is up, increasing clockwise; so right is 90 degrees."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 25,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def init_mowmaster():\n",
+    "    return {'x': 0, 'y': 0, 'd': 90}"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Execute the instructions. Do them one at a time, updating the mowmaster for each one.\n",
+    "\n",
+    "(Can you see an accumulator pattern again?)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 26,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def execute(mowmaster, instructions, debug=False):\n",
+    "    for instruction in instructions:\n",
+    "        mowmaster = execute_one(mowmaster, instruction, debug=debug)\n",
+    "    return mowmaster"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Execute one instruction. If it starts `C` or `A`, turn; if it starts `F`, move forward. Ignore all other instructions."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 27,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def execute_one(mowmaster, instruction, debug=False):\n",
+    "    if instruction == 'C':\n",
+    "        mowmaster['d'] = (mowmaster['d'] + 90) % 360 # Use the modulus operator to keep the angle in the range 0--360\n",
+    "    elif instruction == 'A':\n",
+    "        mowmaster['d'] = (mowmaster['d'] - 90) % 360\n",
+    "    elif instruction.startswith('F'):\n",
+    "        mowmaster = move(mowmaster, int(instruction[1:]))\n",
+    "    if debug: \n",
+    "        print(instruction, mowmaster)\n",
+    "    return mowmaster"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The movement. Update `x` or `y` depending on the direction."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 28,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -131,18 +244,15 @@
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": 12,
+   "cell_type": "markdown",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "def init_mowmaster():\n",
-    "    return {'x': 0, 'y': 0, 'd': 90}"
+    "Finally, how far the Mowmaster has moved."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 16,
+   "execution_count": 29,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -151,27 +261,15 @@
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": 13,
+   "cell_type": "markdown",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "def execute(mowmaster, instructions, debug=False):\n",
-    "    for instruction in instructions:\n",
-    "        if instruction == 'C':\n",
-    "            mowmaster['d'] = (mowmaster['d'] + 90) % 360\n",
-    "        elif instruction == 'A':\n",
-    "            mowmaster['d'] = (mowmaster['d'] - 90) % 360\n",
-    "        elif instruction.startswith('F'):\n",
-    "            mowmaster = move(mowmaster, int(instruction[1:]))\n",
-    "        if debug: \n",
-    "            print(instruction, mowmaster)\n",
-    "    return mowmaster"
+    "Now we have all the parts, put them together into the solution."
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 18,
+   "execution_count": 30,
    "metadata": {},
    "outputs": [
     {
@@ -180,7 +278,7 @@
        "337"
       ]
      },
-     "execution_count": 18,
+     "execution_count": 30,
      "metadata": {},
      "output_type": "execute_result"
     }