2 files changed, 62 insertions, 0 deletions
diff --git a/2/2.ha b/2/2.ha
new file mode 100644
index 0000000..83ba3b8
--- /dev/null
+++ b/2/2.ha
@@ -0,0 +1,56 @@
+use fmt;
+use bufio;
+use os;
+use strings;
+use strconv;
+
+export fn main() void = {
+	const sc = bufio::newscanner(os::stdin);
+	defer bufio::finish(&sc);
+
+	let safereports = 0;
+	for (const line => bufio::scan_line(&sc)!) {
+		const spl = strings::split(line, " ");
+		defer free(spl);
+		let safe = true;
+		let inc: (bool | void) = void;
+		for (let i = 1z; i < len(spl); i += 1) {
+			const s1 = strconv::stoi(spl[i-1])!;
+			const s2 = strconv::stoi(spl[i])!;
+			const diff = if (s1 < s2) {
+				match (inc) {
+				case void =>
+					inc = true;
+				case let inc: bool =>
+					if (!inc) {
+						safe = false;
+						break;
+					};
+				};
+				yield s2 - s1;
+			} else {
+				match (inc) {
+				case void =>
+					inc = false;
+				case let inc: bool =>
+					if (inc) {
+						safe = false;
+						break;
+					};
+				};
+				yield s1 - s2;
+			};
+			if (diff <= 0 || diff > 3) {
+				safe = false;
+				break;
+			};
+		};
+		if (safe) {
+			fmt::printfln("{}: Safe", line)!;
+			safereports += 1;
+		} else {
+			fmt::printfln("{}: Unsafe", line)!;
+		};
+	};
+	fmt::printfln("{} reports are safe", safereports)!;
+};
diff --git a/2/in b/2/in
new file mode 100644
index 0000000..b49c10d
--- /dev/null
+++ b/2/in
@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9