From 9b6e79bc3b725f137c5df46d03816343f41bb128 Mon Sep 17 00:00:00 2001
From: Thomas Schmucker <ts@its1.de>
Date: Mon, 11 Nov 2024 20:30:23 +0100
Subject: aoc 2015, day03

---
 2015/src/day03.cpp | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 2015/src/day03.cpp

(limited to '2015')

diff --git a/2015/src/day03.cpp b/2015/src/day03.cpp
new file mode 100644
index 0000000..e81da90
--- /dev/null
+++ b/2015/src/day03.cpp
@@ -0,0 +1,93 @@
+#include <fstream>
+#include <iostream>
+#include <set>
+#include <string>
+
+using namespace std;
+
+auto
+read_file(string_view filename)
+{
+	fstream input{ filename };
+	return string{ istreambuf_iterator<char>{ input }, {} };
+}
+
+void
+part1(string_view directions)
+{
+	set<tuple<int, int>> positions{};
+	int                  xpos = 0;
+	int                  ypos = 0;
+
+	positions.emplace(xpos, ypos);
+	for ( const auto direction: directions ) {
+		switch ( direction ) {
+		case '^':
+			--ypos;
+			break;
+		case 'v':
+			++ypos;
+			break;
+		case '<':
+			--xpos;
+			break;
+		case '>':
+			++xpos;
+			break;
+		default:
+			break;
+		}
+		positions.emplace(xpos, ypos);
+	}
+	cout << positions.size() << endl;
+}
+
+void
+part2(string_view directions)
+{
+	set<tuple<int, int>> positions{};
+
+	for ( string_view::size_type start = 0; start != 2; ++start ) {
+		int xpos = 0;
+		int ypos = 0;
+
+		positions.emplace(xpos, ypos);
+
+		for ( string_view::size_type idx = start; idx < directions.length(); idx += 2 ) {
+			const auto direction = directions[idx];
+
+			switch ( direction ) {
+			case '^':
+				--ypos;
+				break;
+			case 'v':
+				++ypos;
+				break;
+			case '<':
+				--xpos;
+				break;
+			case '>':
+				++xpos;
+				break;
+			default:
+				break;
+			}
+			positions.emplace(xpos, ypos);
+		}
+	}
+	cout << positions.size() << endl;
+}
+
+int
+main()
+{
+	auto directions = read_file("data/day03.txt");
+	// part1(">");
+	// part1("^>v<");
+	// part1("^v^v^v^v^v");
+	part1(directions);
+	// part2("^v");
+	// part2("^>v<");
+	// part2("^v^v^v^v^v");
+	part2(directions);
+}
-- 
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