test(2018 day-14): tuning buffers exposes a failing test. recipe list is not being constructed correctly.

Author: developher-net

2018/day-14/recipes.js

@@ -111,21 +111,25 @@ const calculateXAfterY = (x, y, recipes, elves) => {
  * @param {String} pattern to search for
  * @param {LinkedList} recipes recipe list
  * @param {Array} elves doing the work
- * @param {Number} bufferSize bucket size to search. Higher sizes use more memory but go faster
+ * @param {Number} bufferSize bucket size to search. Tuning bucket size can improve speed but may risk missing match if the match crosses buckets.
  */
 const findPattern = (pattern, recipes, elves, bufferSize) => {
-  bufferSize = bufferSize || 10000
+  bufferSize = bufferSize || 101
   let matched = false
   let position = recipes.length
   while (matched !== true) {
     let haystack = loopRecipesForElves(elves, recipes, bufferSize)
-    if (haystack.indexOf(pattern) > -1) {
-      position += haystack.indexOf(pattern)
+    let offset = haystack.indexOf(pattern)
+    if (offset > -1) {
+      position += offset
+      console.log(`Found ${pattern} at ${haystack.substr(0, offset + pattern.length)}`)
       matched = true
     } else {
-      position += 1000
+      position += bufferSize
+      console.log(`Did not find ${pattern} before ${position}`)
     }
   }
+
   return position
 }
 

2018/day-14/solution.js

@@ -1,12 +1,13 @@
 const {
   calculateXAfterY,
+  findPattern,
   Recipes
 } = require('./recipes')
 
 const input = 540561
 
-const elves = [3, 7]
-const recipes = new Recipes(elves[0])
+let elves = [3, 7]
+let recipes = new Recipes(elves[0])
 
 elves.forEach((elf, idx) => {
   if (idx === 0) {
@@ -17,9 +18,20 @@ elves.forEach((elf, idx) => {
 })
 
 const answer = calculateXAfterY(10, input, recipes, elves)
-const answer2 = ''
 
 console.log(`-- Part 1 --`)
 console.log(`Answer: ${answer}`)
+
+elves = [3, 7]
+recipes = new Recipes(elves[0])
+elves.forEach((elf, idx) => {
+  if (idx === 0) {
+    elves[0] = recipes.head
+  } else {
+    elves[idx] = recipes.addRecipe(elf)
+  }
+})
+const bufferSize = 10001
+const answer2 = findPattern(input.toString(), recipes, elves, bufferSize)
 console.log(`-- Part 2 --`)
 console.log(`Answer: ${answer2}`)