Day 6

6/input

@@ -0,0 +1 @@
+hqhnqhqshhslswsffchfcfbblvlblqlggfwwqfwwqdddbbbhzhjjrqjqbjqjwqjwqwhwrrmcrrjqjjlllcvcrrnpptzpzmmswmmzrzjrrfcrfccpbpzzvrrdndllttwftwwgzzwhwggdvdnnlrnncscbcfcctchcdchdccztzgzjjtdtcdtcchrrgpgzgsgpsggvtvppdccfhcfclfcfdfnddlbbptbtdbtdtjdjgdjjzljlssgbgcgqcqzccfnftfjjsgstggsngsscvssjzjnjtntvnvssrqqhtqtvqtvvjbvvbnvvqvmvrmmdsdvdwwnbnvbnvvcgvcczcfzftfsfrfsfttldtdrrgrgmgbbdvvbqbhqbqlqsqbsbpbgbvgbgwwrswrwrwttvnnzdnzzwggrmrfmmvllzwlwzzlvlbvllgsllpnlnvncvcvqqrwwcmcczhchzczbccdwcwvwzwwvddlwlhljlqjqnncntnctczzmwmlmccpggljlssqswsmmpvmvwvrrcpcrprmprrtdrtdrrsjsmshmmdpdlppbnbvvmmflmmjvjhvhjvjsjbjwjvvblvbvlbbllwlslvljvlvdvdgvgcchnhpnhnvhhtfhhvssczztlzzgvvqqghqgqssdscsnsrsmrmmwgwmgmlmdmggbgzbgzgdzdzccghgfgddtntftddpdrdrmrjmmmzttqmttnwngggtgtqtqnqhnqqpnnntrntrnnshhjtjzzfqqblqqlblslflmlttcwtwzzrlrnrcrrrgtrrftfhthzhggwggvgvvfvddcnddfjddzqzrrvtrvrfrrgpgrgngsgddlmddzgzppdzzjzhjhjhqqbpbvvlrvrsvrvnrrsgsttndnbngnppmlppvgvfggvcvrvnnsnfnnfqfwwppnddrrfqqgbqqfmmlnlnngwgcgjgnjgjsgjgqjjnccdttpqttswwcgcmgmccrppmqmbbfwwvdwdfwfjwfjjblldsdrdvvgcvcwwllfpllcslsvssnvsnvvhnvnvwwcgwccslsbbnlbnbrrrtprptpdpdvdttgsgwswppcdchhqbqcbqbzbgbbstshthsttqgtqtpqqzhhwhghwwmbbdlbbtlltsllbvbnvvmqvqtvqvttlwtltmmrttwgtwwfdddwcchtchhbthbbclczzqbzzpvvwzwswggjddntnrnnwmnnbdbmbccqgqvvsnvvqbvbzvvzmvzzrfrlfrfhhdvddnmnnmhmqhhrhlrldljlbljjgqqvdvhhgmgvgddmmznndmmhssznsswvwdvdzdhhscssntnftfmmrggbmbmgmlltctbtbntnqqscqcscrcrhrlhhdchhzccvvbfvvpfffbwbsbjjmgmwgmgppjnpjphhlmhhpwwhwzhhhzbbzzcbchhpnnptpvphhsdsccffqbqllchlhlwlcljlppnccqsstzstswtwwljwjmmpttvqqspsjjclljqqlhqqtnnbrrsbrbjjllrmrjmjzmmclmclmmcvvbddhnnmhmbbwqqqhrqqtqmqbqdbdtdvvcscshccmffhqffdgdcgddljdjbdbjbdbrrtjjtnntpntpnpmnpmpgghffrnfrnnmdnmnhmmjcjffftrrttfwfvwvcwwrmwmpwmmnvntthmmgmbbcdclcppjhpjhjwwlppgsszqqwggmttfrfqflfsfmmmhchshmmjtjjgdjjnnsvsmsnwcgdfqljmnphlfdrhpggfqnhnszgpndhdqcgfhtdcgbsbtmhvnnrmqzqqcjdqndzbnrhwjvbvcldmnwltgpqbmstntnggtbqjzzqrfdsfttdfrcnsrpwrjrjqbgtjfmlwsrzdbdqvbtczgsjqhtgmctjfmdglfrsvqtgwpbqghzgzdfwzhbdhlmhdvhwjrdhhtjptvwpmjnmfcjdmdczmczvdqwvbgtvlwvwnvdlbqfshmlmvzzcmjbtpwpwgsqhfsgljzhbppcztfjdntzcvllqnzrqjwfjrlgvhmbpvbtqjrdzcsmcjzcdsmvcmhrbhgnscnfrfmscqsqpqplbrzhsrlsvvpmfdtdmtlrtvspmlljmfpshfmstjgnrrwmqlbnwbndcfdstrtqtnzpfqlcgrzmsnmhllljdgtmvftjttbwhqzcqwbwdbshgcqrptfjwbbfsjnvzztlbdchqrlbbrcnsswmhwphfwrbnvrncbrthprmltlwwlfpbqhdfqzwwcwjgqzdnvmhwpzpbtpwwvzcpfcsfqpwjljzzfwzmlfvhsccppzlzjlrvlpdtjpcptnvqjwtdbzrqwnfwmmjndflqqggczrfjlpdfjffctprnmhfdqvnzbfvhszzdmngnlmwzfdrbvlvjnmbllgrczssqcrhbmnpmqlrzgmqmhgsvcdlqnmlhlzvqzhnccbctslzlbcpdvqltqncpcrzwdchrqmwfwlcbcvfnnpjntfrznqdjsdtzqjjttddwvnfqmznhflblzvvtbwdzrrlqlmndzzzwnpbhhlvlbswfjtbnhlccscbnfgjtwbfdlwvzszwnwzhlbcdpvgqjcrpzsvvnfwqcqvrmhzhggvmzwggdpbfrdscjwhsdsbbjcnzldhzcvqtjrhsbfjlrlpvtcqhnnsvslfrdjvjhfhdcfzqchpvvhzbpqglqlrdttrdtndzhnzhtqndghtgmpsnhptprqzhbbdcrgmbvrvqmbptqgnmsccwmhrlpddvmhjntllwrzqwnsjchnblcgndjtmpswwgcstdftqcbhzgttrhnpvrhspjznhhvrlpdqbzzrvzjphcswhljdldvsrdhzltwgrcsvqwnhtqqjjrjgrplzmsnjhzrfbtqgdfgnbpvjrfzrrpdphgzrfbswdhzgbzswqtwwdtrvvswmjvwhqddfzjhgdqsfnwbmlcfwtmpldrdpwjwggbpmncvbghzjmpsqpvnmbhjfzzpsjdgmrtnndhzrphjzdbgrrnthtrfnspdngbdmwbnfjlsndqswfsvfqftqlgqjpfsfpmdbsjfrptvbpvflqgvlmmbchhghhrwmvdlrhlsdtvjjchwglcrwfsfnnbhjbtccbjsfwrbzrvgsbfnvzghhrqblqchjvdtrrbrwwwmfnczzmmrqdggsfrqbldbbfbbcthtsvpcnlbjjztwvhctbrjltqdwbzmrrfslbmjpnqwllbvjzgfsfqqtwbgwgclgdflshfhwggwdqlgbmdmdqglrtfwbddtsltmsvswhgjtqwtnrncpdzhnpfqcjnjzmtbjfzpjwgfbfggmsmfdhfbjctnhchpgfspthdbfpmvrmdbbspvwzqqwnmfwdnnblbcjszbccgflngnjjwsqshfbhjwgzrmvsgnrdbgwfhdvpmznpnvznfcqdclztcptjrrpbmpztwwbvlvtmngfhmfbfmrjbjzlrcvgllrlgthltstnwmffntqrwsrndlzqhztwpcwbdjjztgdzmgtthcvtvnjzzhvstfqhgddddgdsrbcqzqspjrncphhtbnslzphrtfqphffjrrlgwbrwqfzzqvzhnffcwvrncttgplshccglvchvlcbnlthhmzvcrfjvjqfsjjzzgqlpslfwngqnbgcwffpcqhlmlhvwssrpjbrcbftpzbbpptzrdqwpzpdjhtwbvwcqbfnwtflfgzgttglpcwdnzsmjffgfftdnpzlpszmzrrhvlzdfpgbzqlvvfslnndcmjvvpwzwcdzpcttfwbsdswmfqbbhbfbjvbvtspbbhmphzjsjcmmzpvvzhtvzlgwlqqvbnrgtszvghjfmchrwwhpmbsvfmgvqdtmvdtjppchbsgqrtgtnzczqmpgjdbmmflfpjbcdmhldwpgdtdvsbzhztjzfhcsbndfjntbldjnqwdffqspfnlplbtcdjtwdjhldtsdfrnmpfhzghnpcqlhhgblmqjvwhndqfbccvzzlbzbdprvcpwjjhrqnjptwssbjhgvpgtfzqwrzjvbdgwtnmptvdjrffcmbzmzcmrfbjv

6/solution.mjs

@@ -0,0 +1,32 @@
+import { readFileSync } from 'node:fs';
+
+const input = readFileSync('input', 'utf-8');
+
+function isValidMarker(marker) {
+  return marker.split('').every((c, i, word) => word.lastIndexOf(c) === i);
+}
+
+function findMarker(markerLength) {
+  for (let pos = markerLength; pos <= input.length; pos++) {
+    const marker = input.slice(pos - markerLength, pos);
+    if (isValidMarker(marker)) {
+      return { marker, pos };
+    }
+  }
+}
+
+const packetMarker = findMarker(4);
+if (packetMarker) {
+  console.log(
+    `Found packet marker: ${packetMarker.marker} after: ${packetMarker.pos} ` +
+    `characters`
+  );
+}
+
+const messageMarker = findMarker(14);
+if (messageMarker) {
+  console.log(
+    `Found message marker: ${messageMarker.marker} after: ` +
+    `${messageMarker.pos} characters`
+  );
+}