day 2 ;(

2024/02/p1/main.zig

@@ -0,0 +1,37 @@
+const std = @import("std");
+
+pub fn main() !void {
+    var file = try std.fs.cwd()
+        .openFile("../input.txt", .{});
+    defer file.close();
+
+    var buf_reader = std.io.bufferedReader(file.reader());
+    var in_stream = buf_reader.reader();
+
+    var buf: [64]u8 = undefined;
+    var t: u32 = 0;
+    while (try in_stream.readUntilDelimiterOrEof(&buf, '\n')) |line| {
+        var split_iter = std.mem.split(u8, line, " ");
+
+        var dir: i8 = 0;
+        var prev = try std.fmt.parseInt(i8, split_iter.next() orelse unreachable, 10);
+        t += while (split_iter.next()) |strnum| {
+            const n = try std.fmt.parseInt(i8, strnum, 10);
+            const d = prev - n;
+            prev = n;
+            if (d == 0 or @abs(d) > 3)
+                break 0;
+
+            if (dir == 0) {
+                dir = d;
+            } else if (!sameSign(dir, d)) {
+                break 0;
+            }
+        } else 1;
+    }
+    std.debug.print("Total {d}\n", .{t});
+}
+
+pub fn sameSign(n1: i8, n2: i8) bool {
+    return (n1 < 0) == (n2 < 0);
+}