day01

6 files changed, 85 insertions, 0 deletions

diff --git a/day01/Makefile b/day01/Makefile
new file mode 100644
index 0000000..2fa98c0
--- /dev/null
+++ b/day01/Makefile
@@ -0,0 +1 @@
+include ../aoc.mk
diff --git a/day01/solution.cpp b/day01/solution.cpp
new file mode 100644
index 0000000..9fb9ec1
--- /dev/null
+++ b/day01/solution.cpp
@@ -0,0 +1,69 @@
+#include <bits/stdc++.h>
+
+namespace views = std::views;
+namespace ranges = std::ranges;
+
+auto parse_input(std::istream& is) {
+    const std::string input = {
+        std::istreambuf_iterator<char>(is),
+        std::istreambuf_iterator<char>()
+    };
+
+    auto lines = views::split(input, '\n') | views::filter([](auto line) { return not line.empty(); });
+    std::vector<int> document;
+    for (auto const line : lines) {
+        char direction = line[0];
+        std::string out;
+        ranges::copy(line | views::drop(1), std::back_inserter(out));
+        int length = std::stoi(out);
+        document.push_back(direction == 'R' ? length : -length);
+    }
+    return document;
+}
+
+int const DIAL_MAX = 100;
+
+void part1(auto const& input) {
+    // Write first part solution here
+    int answer = 0;
+    int dial = 50;
+
+    for (auto const offset : input) {
+        dial += offset;
+        dial %= DIAL_MAX;
+        if (dial == 0) {
+            ++answer;
+        }
+    }
+
+    std::println("{}", answer);
+}
+
+void part2(auto const& input) {
+    // Write second part solution here
+    int answer = 0;
+    int dial = 50;
+    int sign = 1;
+
+    for (auto const offset : input) {
+        int old_dial = dial;
+        dial += offset;
+        answer += std::abs(dial / DIAL_MAX);
+        if (old_dial * dial < 0 or dial == 0) {
+            ++answer;
+        }
+        dial %= DIAL_MAX;
+        old_dial = dial;
+        std::cerr << answer << ' ' << dial << '\n';
+    }
+    std::println("{}", answer);
+}
+
+int main() {
+    auto const input = parse_input(std::cin);
+
+    part1(input);
+    part2(input);
+
+    return 0;
+}
diff --git a/day01/tests/test1.input b/day01/tests/test1.input
new file mode 100644
index 0000000..53287c7
--- /dev/null
+++ b/day01/tests/test1.input
@@ -0,0 +1,10 @@
+L68
+L30
+R48
+L5
+R60
+L55
+L1
+L99
+R14
+L82
diff --git a/day01/tests/test1.output b/day01/tests/test1.output
new file mode 100644
index 0000000..2559e5c
--- /dev/null
+++ b/day01/tests/test1.output
@@ -0,0 +1,2 @@
+3
+6
diff --git a/day01/tests/test2.input b/day01/tests/test2.input
new file mode 100644
index 0000000..af158bd
--- /dev/null
+++ b/day01/tests/test2.input
@@ -0,0 +1 @@
+L150
\ No newline at end of file
diff --git a/day01/tests/test2.output b/day01/tests/test2.output
new file mode 100644
index 0000000..1191247
--- /dev/null
+++ b/day01/tests/test2.output
@@ -0,0 +1,2 @@
+1
+2