Day 2 part 2

day-2/main.zig

@@ -10,7 +10,7 @@ pub fn define_direction(num1: i32, num2: i32) i8 {
     }
 }
 
-pub fn main() !void {
+pub fn part_1() !void {
     var file = try std.fs.cwd().openFile("input.txt", .{});
     defer file.close();
 
@@ -28,7 +28,6 @@ pub fn main() !void {
         var direction: i8 = 0;
         var tokAny = std.mem.tokenizeAny(u8, line, " ");
         while (tokAny.next()) |num| {
-            std.debug.print("{s} ", .{num});
             const n = try std.fmt.parseInt(i32, num, 10);
             if (first_round) {
                 last_num = n;
@@ -52,11 +51,84 @@ pub fn main() !void {
             }
             last_num = n;
         }
-        std.debug.print("\n", .{});
 
         if (is_safe) {
             safe_reports += 1;
         }
     }
-    std.debug.print("{}", .{safe_reports});
+    std.debug.print("Part 1: {}\n", .{safe_reports});
+}
+
+pub fn part_2() !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 safe_reports: u32 = 0;
+
+    var buf: [2048]u8 = undefined;
+    while (try in_stream.readUntilDelimiterOrEof(&buf, '\n')) |line| {
+        var is_safe = true;
+        var round: i32 = -1;
+        var last_num: i32 = 0;
+        var defined_direction = false;
+        var direction: i8 = 0;
+        var shield = true; // very bad name lol
+        var tokAny = std.mem.tokenizeAny(u8, line, " ");
+        while (tokAny.next()) |num| {
+            round += 1;
+            const n = try std.fmt.parseInt(i32, num, 10);
+            if (round == 0) {
+                defined_direction = false;
+                last_num = n;
+                continue;
+            }
+            if (@abs(last_num - n) > 3) {
+                if (shield) {
+                    if (round == 1) {
+                        defined_direction = false;
+                        last_num = n;
+                    }
+                    shield = false;
+                    continue;
+                }
+                is_safe = false;
+                break;
+            }
+
+            const current_direction = define_direction(last_num, n);
+
+            if (!defined_direction) {
+                direction = current_direction;
+                if (current_direction != 0) {
+                    defined_direction = true;
+                }
+            }
+            if (current_direction != direction or current_direction == 0) {
+                if (shield) {
+                    if (round == 2) {
+                        defined_direction = false;
+                        last_num = n;
+                    }
+                    shield = false;
+                    continue;
+                }
+                is_safe = false;
+                break;
+            }
+            last_num = n;
+        }
+
+        if (is_safe) {
+            safe_reports += 1;
+        }
+    }
+    std.debug.print("Part 2: {}\n", .{safe_reports});
+}
+
+pub fn main() !void {
+    try part_1();
+    try part_2();
 }