feat(2018 day-08): tally the values for part 2

Author: developher-net

2018/day-08/license.js

@@ -24,6 +24,22 @@ const findChildren = (input, expected) => {
       }
     }
 
+    // Calculate the value of the node (Part 2)
+    result.value = 0
+    if (result.children.length < 1) {
+      // No children, total the metadata
+      result.value = result.metadata.reduce((acc, curr) => { return acc + curr }, 0)
+    } else {
+      // Has children, use the metadata as off-by-one keys to total children's values
+      // metadata = 0 means no child, 1 is first child, 2 is second, etc
+      // We iterate instead of map() because metadata keys can be repeated
+      result.metadata.forEach((key) => {
+        if (typeof result.children[key - 1] !== 'undefined') {
+          result.value += result.children[key - 1].value
+        }
+      })
+    }
+
     results.push(result)
   }
 

2018/day-08/license.test.js

@@ -18,18 +18,22 @@ describe('--- Day 8: Memory Maneuver ---', () => {
           children: [
             {
               children: [],
-              metadata: [10, 11, 12]
+              metadata: [10, 11, 12],
+              value: 33
             }, {
               children: [
                 {
                   children: [],
-                  metadata: [99]
+                  metadata: [99],
+                  value: 99
                 }
               ],
-              metadata: [2]
+              metadata: [2],
+              value: 0
             }
           ],
-          metadata: [1, 1, 2]
+          metadata: [1, 1, 2],
+          value: 66
         }
         const actual = parseData(testData)
         expect(actual).to.deep.equal(expected)
@@ -43,4 +47,7 @@ describe('--- Day 8: Memory Maneuver ---', () => {
       })
     })
   })
+  describe('Part 2:', () => {
+    describe('values on each node covered in data parsing in Part 1. Nothing additional to test.', () => {})
+  })
 })

2018/day-08/solution.js

@@ -7,7 +7,7 @@ const {
 const init = (data) => {
   data = parseData(data)
   const answer = sumMetadata(data)
-  const answer2 = ''
+  const answer2 = data.value
   console.log(`-- Part 1 --`)
   console.log(`Answer: ${answer}`)
   console.log(`-- Part 2 --`)