Advent of Code in Rust 🦀

Complete solutions of Advent of Code in Rust, and sometimes in Python 3.10+ and other languages 🎄✨.

Made for fun 😎 and to practice Rust. Many thanks to Eric Wastl.

2025 (current event) (Calendar) (Solutions) : 24⭐

Puzzle	Stars	Languages
Day 1: Secret Entrance	⭐⭐
Day 2: Gift Shop	⭐⭐
Day 3: Lobby	⭐⭐
Day 4: Printing Department	⭐⭐
Day 5: Cafeteria	⭐⭐
Day 6: Trash Compactor	⭐⭐
Day 7: Laboratories	⭐⭐	🎁
Day 8: Playground	⭐⭐
Day 9: Movie Theater	⭐⭐	🎁
Day 10: Factory	⭐⭐
Day 11: Reactor	⭐⭐
Day 12: Christmas Tree Farm	⭐⭐

All years

Calendar	Solutions	Stars	Rust	Python	🎁
Advent of Code 2025	Solutions	24⭐	12	5	2
Advent of Code 2024	Solutions	50⭐	25	11	3
Advent of Code 2023	Solutions	50⭐	25	10	2
Advent of Code 2022	Solutions	50⭐	25	18	1
Advent of Code 2021	Solutions	50⭐	25	11
Advent of Code 2020	Solutions	50⭐	25	23
Advent of Code 2019	Solutions	50⭐	25	23	2
Advent of Code 2018	Solutions	50⭐	25	4	1
Advent of Code 2017	Solutions	50⭐	25	17
Advent of Code 2016	Solutions	50⭐	25	0
Advent of Code 2015	Solutions	50⭐	25	5	1

Bonus 🎁

Year	Count	Days
2025	2	7 9
2024	3	14 15 16
2023	2	10 14
2022	1	17
2019	2	13 15
2018	1	18
2015	1	18

Timings

day	2015	2016	2017	2018	2019	2020
1	7 µs	30 µs	715 µs	4 ms	6 µs	242 µs
2	87 µs	32 µs	16 µs	4 ms	712 µs	262 µs
3	278 µs	122 µs	906 µs	13 ms	12 ms	16 µs
4	99 ms	2 ms	734 µs	95 µs	27 ms	240 µs
5	1 ms	818 ms	50 ms	5 ms	22 µs	59 µs
6	5 ms	13 µs	865 µs	265 ms	4 ms	831 µs
7	2 ms	27 ms	704 µs	92 µs	485 µs	3 ms
8	28 µs	417 µs	819 µs	154 µs	35 µs	414 µs
9	16 ms	378 µs	57 µs	93 ms	3 ms	118 µs
10	26 ms	545 µs	48 µs	510 µs	5 ms	10 µs
11	6 ms	18 ms	7 ms	119 ms	1 ms	213 ms
12	829 µs	108 ms	2 ms	277 µs	8 ms	29 µs
13	102 ms	26 µs	84 ms	4 ms	9 ms	8 µs
14	841 µs	1154 ms	5 ms	136 ms	4 ms	4 ms
15	6 ms	3 ms	320 ms	94 ms	4 ms	1335 ms
16	126 µs	88 ms	12 ms	756 µs	180 ms	877 µs
17	31 ms	21 ms	138 µs	2 ms	2 ms	27 ms
18	20 ms	162 ms	5 ms	24 ms	85 ms	212 µs
19	503 µs	1 µs	86 µs	7 ms	21 ms	112 ms
20	396 ms	100 µs	29 ms	1 ms	40 ms	823 µs
21	61 µs	2 ms	33 ms	213 µs	5 ms	300 µs
22	2 ms	698 µs	144 ms	41 ms	11 µs	95 ms
23	25 µs	184 µs	2 ms	952 µs	2 ms	142 ms
24	17 ms	3 ms	65 ms	17 ms	32 ms	46 ms
25	74 ms	20 ms	196 ms	1 ms	16 ms	113 µs

day	2021	2022	2023	2024	2025
1	27 µs	48 µs	168 µs	104 µs	62 µs
2	42 µs	103 µs	158 µs	292 µs	931 µs
3	80 µs	65 µs	132 µs	686 µs	387 µs
4	155 µs	300 µs	242 µs	322 µs	3 ms
5	753 µs	401 µs	48 µs	4 ms	54 µs
6	5 µs	877 µs	3 µs	10 ms	31 µs
7	285 µs	251 µs	18 ms	53 ms	371 µs
8	751 µs	558 µs	2 ms	98 µs	15 ms
9	495 µs	639 µs	419 µs	244 ms	4 ms
10	64 µs	13 µs	24 ms	430 µs	5 ms
11	223 µs	5 ms	1 ms	9 ms	209 µs
12	34 ms	820 µs	51 ms	4 ms	47 ms
13	1 ms	776 µs	252 µs	56 µs
14	609 µs	10 ms	49 ms	20 ms
15	37 ms	490 ms	350 µs	1 ms
16	26 µs	3 ms	24 ms	258 ms
17	94 ms	1 ms	155 ms	7 µs
18	6 ms	2 ms	53 µs	435 µs
19	4 ms	1094 ms	2 ms	65 ms
20	97 ms	100 ms	3 ms	28 ms
21	3 ms	610 µs	4 ms	843 µs
22	78 ms	6 ms	7 ms	141 ms
23	228 ms	151 ms	200 ms	129 ms
24	70 ms	92 ms	635 µs	224 µs
25	68 ms	14 µs	209 ms	499 µs

Total : 11.953 s

Under the hood 🎄

All solutions are tested and verified with a lot of puzzle inputs and answers (personal accounts, family accounts, friends' accounts and those found on GitHub). Thus, they can be considered totally generic.

By choice, I use the most recent versions of the languages, and therefore sometimes new paradigms and functionalities, since AoC is an excellent way to practice, explore and learn (while having fun!).

Rust solutions respect cargo clippy -- -D clippy::all -F clippy::pedantic -F clippy::nursery, which is a pretty strong hardening.

They also include, for the most part, unit tests taken from the examples of puzzle statements.

Timings are measured for the Rust solutions with my puzzle inputs, on a Macbook Pro M1 (2020).