From e3fe1fd7335c3834c2266ea9c94796699b7aa286 Mon Sep 17 00:00:00 2001
From: Christopher Bohn <bohn@unl.edu>
Date: Tue, 6 Dec 2022 08:00:33 -0600
Subject: [PATCH] Completed Year 2022 Day 6 Part 1
---
2022/README.md | 14 +++++
.../java/edu/unl/cse/bohn/year2022/Day6.java | 51 +++++++++++++++++++
2 files changed, 65 insertions(+)
create mode 100644 2022/src/main/java/edu/unl/cse/bohn/year2022/Day6.java
diff --git a/2022/README.md b/2022/README.md
index 214ea26..46dd6d6 100644
--- a/2022/README.md
+++ b/2022/README.md
@@ -161,5 +161,19 @@ techniques should be used.
## Day 6
+- [The problem](https://adventofcode.com/2022/day/6)
+- [The solution](src/main/java/edu/unl/cse/bohn/year2022/Day6.java)
+
+### Part 1
+
+The subproblems are
+- Identify the first sequence of four unique characters in a string
+ - Assume there is such a sequence
+ - Determine when a sequence of four characters contain duplicates
+- Count the number of characters before the next character after that sequence
+ - *i.e.*, count the number of characters before that sequence plus the four characters in that sequence
+
+## Day 7
+
(coming soon)
diff --git a/2022/src/main/java/edu/unl/cse/bohn/year2022/Day6.java b/2022/src/main/java/edu/unl/cse/bohn/year2022/Day6.java
new file mode 100644
index 0000000..b33b4ac
--- /dev/null
+++ b/2022/src/main/java/edu/unl/cse/bohn/year2022/Day6.java
@@ -0,0 +1,51 @@
+package edu.unl.cse.bohn.year2022;
+
+import edu.unl.cse.bohn.Puzzle;
+
+import java.util.*;
+
+@SuppressWarnings("unused")
+public class Day6 extends Puzzle {
+ @SuppressWarnings({"SpellCheckingInspection", "CommentedOutCode"})
+ public Day6(boolean isProductionReady) {
+ super(isProductionReady);
+// sampleData = "mjqjpqmgbljsphdztnvjfqwrcgsmlb";
+// sampleData = "bvwbjplbgvbhsrlpgdmjqwftvncz";
+// sampleData = "nppdvjthqldpwncqszvftbrmjlhg";
+// sampleData = "nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg";
+ sampleData = "zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw";
+ }
+
+ @Override
+ public long computePart1(List<String> data) {
+ return getStartOfPacketIndex(data.get(0));
+ }
+
+ @Override
+ public long computePart2(List<String> data) {
+ return 0;
+ }
+
+ private long getStartOfPacketIndex(String dataStream) {
+ LinkedList<Character> markerCandidate = new LinkedList<>();
+ int nextIndex = 0;
+ int indexOfDuplicate = Integer.MIN_VALUE;
+ boolean foundMarker = false;
+ while (!foundMarker) {
+ char c = dataStream.charAt(nextIndex++);
+// System.out.print(markerCandidate + " + " + c + " = ");
+ int indexOfPossibleDuplicate = markerCandidate.lastIndexOf(c);
+ indexOfDuplicate = Integer.max(indexOfDuplicate, indexOfPossibleDuplicate);
+ markerCandidate.add(c);
+ if (nextIndex > 4) {
+ markerCandidate.remove();
+ indexOfDuplicate--;
+ if (indexOfDuplicate < 0) {
+ foundMarker = true;
+ }
+ }
+// System.out.println(markerCandidate);
+ }
+ return nextIndex;
+ }
+}
--
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