main.zig contains code for main runner.

src/dayX.zig contain solutions for each day. Every file has 2 public functions runPart1 and runPart2 for parts 1 and 2 respectively.

1. Change needed day in main.zig.
2. cat input | zig build run.

zig test src/dayX.zig

At some point tests are written only for examples, because I had no time.