This year I want to complete each day without brute force. I will see how long that lasts.
For day 1, go to https://adventofcode.com/2025/day/1/input to see your input for the day. ctrl+a and copy paste into day01/input.txt.
The process is the same for the other days.
Make sure you have Zig 0.15
To build a specific day, cd into that day's folder, and run:
zig buildTo run the executable, use either
zig build runor
./zig-out/bin/adventofcodeTo build with optimizations, run
zig build -Doptimize=ReleaseFastThe root folder has its own build script, running zig build in the root folder will build all day's solutions.
Running the time step will use hyperfine to time each day's solution. I will try my best to keep each day under 1ms on my laptop.
zig build -Doptimize=ReleaseFast timeThese are the speeds on my laptop.
| day | Time (mean ± σ) | Range (min … max) |
|---|---|---|
| 1 | 285.8 µs ± 79.7 µs | 147.4 µs … 1476.6 µs |
| 2 | 355.2 µs ± 92.7 µs | 190.6 µs … 1679.4 µs |
| 3 | 218.9 µs ± 69.3 µs | 130.3 µs … 1495.9 µs |
| 4 | 490.9 µs ± 111.6 µs | 228.9 µs … 1994.8 µs |
| 5 | 377.8 µs ± 112.9 µs | 210.2 µs … 1877.2 µs |
| 6 | 341.4 µs ± 87.2 µs | 167.7 µs … 1648.7 µs |
| 7 | 172.5 µs ± 57.8 µs | 110.3 µs … 1407.7 µs |