From 2fdbbd79bed58399ab63f92ece74fe6abb450b9c Mon Sep 17 00:00:00 2001
From: Piotr Russ <piotr.russ@betvictor.com>
Date: Sat, 12 Dec 2020 10:38:29 +0100
Subject: day11

---
 day11/day11-2.js | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 day11/day11-2.js

(limited to 'day11/day11-2.js')

diff --git a/day11/day11-2.js b/day11/day11-2.js
new file mode 100644
index 0000000..5d72f0f
--- /dev/null
+++ b/day11/day11-2.js
@@ -0,0 +1,50 @@
+const data = require('./data')
+const rows = data.split(/\n/g).filter(r => r)
+const rowsLn = rows[0].length
+const string = rows.join('')
+
+const checkSeat = (i, s) => {
+  const lookup = (index, posCheck, next) => {
+    const nextIndex = next(index)
+    return posCheck(index)
+      ? (s[nextIndex] !== '.' ? s[nextIndex] : lookup(nextIndex, posCheck, next))
+      : '.'
+  }
+
+  const around = [
+    lookup(i, i => (i >= rowsLn), i => (i-rowsLn)),                                   // Top
+    lookup(i, i => (i >= rowsLn && (i+1)%rowsLn !== 0), i => (i+1-rowsLn)),           // T-R
+    lookup(i, i => ((i+1)%rowsLn !== 0), i => (i+1)),                                 // Rigth
+    lookup(i, i => (i < s.length - rowsLn && (i+1)%rowsLn !== 0), i => (i+1+rowsLn)), // B-R
+    lookup(i, i => (i < s.length - rowsLn), i => (i+rowsLn)),                         // Bottom
+    lookup(i, i => (i%rowsLn !== 0 && i < s.length -rowsLn), i => (i-1+rowsLn)),      // B-L
+    lookup(i, i => (i%rowsLn !== 0), i => (i-1)),                                     // Left
+    lookup(i, i => (i > rowsLn && i%rowsLn > 0), i => (i-1-rowsLn)),                  // T-L
+  ]
+
+  const taken = around.filter(s => s === '#').length
+  const free = around.filter(s => s === 'L').length
+
+  return [taken, free]
+}
+
+const round = (str) => {
+  const newArray = []
+  str.split('').forEach((s, i) => {
+    const [taken, free] = checkSeat(i, str)
+    if (s === 'L' && taken === 0) {
+      newArray[i] = '#'
+    } else if (s === '#' && taken >= 5) {
+      newArray[i] = 'L'
+    } else {
+      newArray[i] = str[i]
+    }
+  })
+
+  const newString = newArray.join('')
+  return newString === str
+    ? newString.split('').filter(s => s === '#').length
+    : round(newString)
+}
+
+console.log(round(string))
-- 
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