From cab6c1ddc066b2af76fac909fde66e3d5b4cdcd8 Mon Sep 17 00:00:00 2001
From: Polesznyák Márk <contact@pml68.dev>
Date: Tue, 2 Dec 2025 22:36:23 +0100
Subject: feat: day2 part1 complete

---
 day2/part1/main.ha | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 day2/part1/main.ha

(limited to 'day2/part1/main.ha')

diff --git a/day2/part1/main.ha b/day2/part1/main.ha
new file mode 100644
index 0000000..aa4675d
--- /dev/null
+++ b/day2/part1/main.ha
@@ -0,0 +1,54 @@
+use fmt;
+use io;
+use math;
+use os;
+use strconv;
+use strings;
+
+fn digits(num: u64) u64 = {
+	return math::ceilf64(math::log10f64(num: f64)): u64;
+};
+
+export fn main() void = {
+	let handle = os::open("input.txt")!;
+	defer io::close(handle)!;
+
+	let buf = io::drain(handle) as []u8;
+	defer free(buf);
+
+	let input = strings::fromutf8_unsafe(buf);
+	let range_strings = strings::split(input, ",")!;
+
+	let answer: u64 = 0;
+
+	for (let i: size = 0; i < len(range_strings); i += 1) {
+		let range_ends = strings::cut(strings::rtrim(range_strings[i], '\n'), "-");
+
+		let start = strconv::stou64(range_ends.0)!;
+		let end = strconv::stou64(range_ends.1)!;
+
+		let start_digits = digits(start);
+		let end_digits = digits(end);
+
+		if (start_digits % 2 != 0 && end_digits % 2 != 0 && start_digits == end_digits) {
+			continue;
+		};
+
+		for (let j = start; j <= end; j += 1) {
+			let digits = digits(j);
+
+			if (digits % 2 == 0) {
+				let num_str = strconv::u64tos(j);
+
+				let first_half = strings::sub(num_str, 0, len(num_str) / 2);
+				let second_half = strings::sub(num_str, len(num_str) / 2, len(num_str));
+
+				if (first_half == second_half) {
+					answer += j;
+				};
+			};
+		};
+	};
+
+	fmt::printfln("Answer: {}", answer)!;
+};
-- 
cgit v1.2.3