1 files changed, 58 insertions, 0 deletions
diff --git a/day17/day17-2.js b/day17/day17-2.js
new file mode 100644
index 0000000..65dea2d
--- /dev/null
+++ b/day17/day17-2.js
@@ -0,0 +1,58 @@
+const data = require('./data')
+const startArray = [[data.split(/\n/g).filter(e => e).map(e => e.split(''))]]
+
+const cycle = (array) => {
+  const l = array[0][0].length
+  const empty = Array(l+2).fill(Array(l+2).fill('.'))
+  const empty2 = Array(l+2).fill('.')
+  const empty3 = Array(array.length + 2).fill(empty)
+  const addDots = ars => ars.map(ar => ([empty2, ...(ar.map(a => ['.', ...a, '.'])), empty2]))
+  const resized = [ empty3, ...array.map(arr => [empty, ...addDots(arr), empty]), empty3]
+  const around = (iw, iz, iy, ix) => {
+    const f = (rw, rz, ry, rx) => {
+      if (
+        !resized[iw+rw]
+        || !resized[iw+rw][iz+rz]
+        || !resized[iw+rw][iz+rz][iy+ry]
+        || !resized[iw+rw][iz+rz][iy+ry][ix+rx]
+      ) { return 0 }
+      return resized[iw+rw][iz+rz][iy+ry][ix+rx] === '#' ? 1 : 0
+    }
+
+    let c = 0
+    for (let w=-1; w<=1; w++) {
+      for (let z=-1; z<=1; z++) {
+        for (let y=-1; y<=1; y++) {
+          for (let x=-1; x<=1; x++) {
+            if (!(x===0 && y===0 && z===0 && w===0)) { c += f(w,z,y,x) }
+          }
+        }
+      }
+    }
+    return c
+  }
+
+  return resized.map((w, iw) => w.map((z, iz) => z.map((y,iy) => y.map((x,ix) => {
+    const active = x === '#'
+    const activeAround = around(iw,iz,iy,ix)
+    if (active) {
+      return (activeAround === 2 || activeAround === 3) ? '#' : '.'
+    } else {
+      return (activeAround === 3) ? '#' : '.'
+    }
+  }))))
+}
+
+let cycleResult = startArray, round = 1
+while (round <= 6) {
+  cycleResult = cycle(cycleResult)
+  round++
+}
+
+let result = 0
+cycleResult.forEach(w => w.forEach(z => z.forEach(y => y.forEach(x => {
+  if (x === '#') {result++}
+}))))
+
+console.log('Answer: ', result)
+