aoc 2024, day 22, part 1

1 files changed, 47 insertions, 0 deletions

diff --git a/2024/src/day22.cpp b/2024/src/day22.cpp
new file mode 100644
index 0000000..b103986
--- /dev/null
+++ b/2024/src/day22.cpp
@@ -0,0 +1,47 @@
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <vector>
+using namespace std;
+
+vector<unsigned long>
+read_file(string_view filename)
+{
+        fstream               input{ filename };
+        vector<unsigned long> lines;
+
+        for ( unsigned long value{}; input >> value; ) {
+                lines.emplace_back(value);
+        }
+
+        return lines;
+}
+
+unsigned long
+step(unsigned long value)
+{
+        value = (value ^ (value * 64)) % 16777216;
+        value = (value ^ (value / 32)) % 16777216;
+        value = (value ^ (value * 2048)) % 16777216;
+        return value;
+}
+
+void
+part1(const vector<unsigned long>& values)
+{
+        unsigned long sum = 0;
+        for ( auto value: values ) {
+                for ( int i = 0; i != 2000; ++i ) {
+                        value = step(value);
+                }
+                sum += value;
+        }
+        cout << sum << endl;
+}
+
+int
+main()
+{
+        auto data = read_file("data/day22.txt");
+        part1(data);
+}