Finish day02, part 1

src/days/day02.zig

@@ -2,6 +2,42 @@ const std = @import("std");
 
 pub const title = "Day 02";
 
-pub fn run(_: std.mem.Allocator) !void {
+pub fn run(allocator: std.mem.Allocator) !void {
+    const input = @embedFile("./input/day02.txt");
+    var ranges = std.mem.tokenizeScalar(u8, input, ',');
+
+    var accumulator: u64 = 0;
+
+    while (ranges.next()) |range| {
+        var components = std.mem.tokenizeScalar(u8, range, '-');
+        const start_s = std.mem.trim(u8, components.next() orelse continue, &std.ascii.whitespace);
+        const end_s = std.mem.trim(u8, components.next() orelse continue, &std.ascii.whitespace);
+        const start = try std.fmt.parseUnsigned(u64, start_s, 10);
+        const end = try std.fmt.parseUnsigned(u64, end_s, 10);
+
+        std.debug.print("{d} to {d}\n", .{start, end});
+
+        outer: for (start..end+1) |id| {
+            const id_s = try std.fmt.allocPrint(allocator, "{}", .{id});
+            defer allocator.free(id_s);
+
+            if (id_s.len % 2 == 1) continue;
+
+            for (0..id_s.len / 2) |i| {
+                if (id_s[i] != id_s[i + id_s.len / 2]) {
+                    continue :outer;
+                }
+            }
+            accumulator += id;
+        }
+    }
+
+    var buffer: [64]u8 = undefined;
+    var stdout_writer = std.fs.File.stdout().writer(&buffer);
+    const stdout = &stdout_writer.interface;
+
+    try stdout.print("{d}\n", .{accumulator});
+
+    try stdout.flush();
 }
 

src/days/input/day02.txt

@@ -0,0 +1 @@
+52500467-52574194,655624494-655688785,551225-576932,8418349387-8418411293,678-1464,33-79,74691-118637,8787869169-8787890635,9898977468-9899009083,548472423-548598890,337245835-337375280,482823-543075,926266-991539,1642682920-1642753675,3834997-3940764,1519-2653,39697698-39890329,3-21,3251796-3429874,3467-9298,26220798-26290827,80-124,200638-280634,666386-710754,21329-64315,250-528,9202893-9264498,819775-903385,292490-356024,22-32,2663033-2791382,133-239,56514707-56704320,432810-458773,4949427889-4949576808