4 files changed, 71 insertions, 0 deletions

diff --git a/day03/Makefile b/day03/Makefile
new file mode 100644
index 0000000..2fa98c0
--- /dev/null
+++ b/day03/Makefile
@@ -0,0 +1 @@
+include ../aoc.mk
diff --git a/day03/solution.cpp b/day03/solution.cpp
new file mode 100644
index 0000000..d90843f
--- /dev/null
+++ b/day03/solution.cpp
@@ -0,0 +1,64 @@
+#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 const lines = views::split(input, '\n')
+        | views::filter([](auto&& line) { return not line.empty(); })
+        | ranges::to<std::vector<std::string>>();
+    return lines;
+}
+
+uint64_t compute_joltage(std::string_view bank, int const njolts) {
+    std::string s_joltage;
+    auto cursor = bank.begin();
+    for (int i = njolts-1; i >= 0; --i) {
+        size_t const begin = std::distance(bank.begin(), cursor);
+        auto const max_elem =
+            ranges::max_element(bank
+                | views::drop(begin)
+                | views::take(bank.size() - begin - i));
+        s_joltage += *max_elem;
+        cursor = max_elem + 1;
+    }
+    return std::stoull(s_joltage);
+}
+
+void part1(auto input) {
+    // Write first part solution here
+    uint64_t answer = 0;
+
+    for (auto bank : input) {
+        answer += compute_joltage(bank, 2);
+    }
+
+    std::println("{}", answer);
+}
+
+void part2(auto input) {
+    // Write second part solution here
+    uint64_t answer = 0;
+
+    for (auto bank : input) {
+        auto const joltage = compute_joltage(bank, 12);
+        answer += compute_joltage(bank, 12);
+    }
+
+    std::println("{}", answer);
+
+}
+
+int main() {
+    auto input = parse_input(std::cin);
+
+    part1(input);
+    part2(input);
+
+    return 0;
+}
diff --git a/day03/tests/test1.input b/day03/tests/test1.input
new file mode 100644
index 0000000..7255fca
--- /dev/null
+++ b/day03/tests/test1.input
@@ -0,0 +1,4 @@
+987654321111111
+811111111111119
+234234234234278
+818181911112111
diff --git a/day03/tests/test1.output b/day03/tests/test1.output
new file mode 100644
index 0000000..8e49ff0
--- /dev/null
+++ b/day03/tests/test1.output
@@ -0,0 +1,2 @@
+357
+3121910778619