diff options
Diffstat (limited to 'aoc19/src/main.rs')
-rw-r--r-- | aoc19/src/main.rs | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/aoc19/src/main.rs b/aoc19/src/main.rs new file mode 100644 index 0000000..f76fce9 --- /dev/null +++ b/aoc19/src/main.rs @@ -0,0 +1,18 @@ +fn main() { + let mut elves = (0..3017957).map(|i| i+1).collect::<Vec<_>>(); + + let mut eliminate_mod = 1; + + while elves.len() > 1 { + let next_mod = if elves.len() % 2 == eliminate_mod { 0 } else { 1 }; + elves = elves.iter() + .enumerate() + .filter(|&(i, _)| i % 2 != eliminate_mod) + .map(|(_, &e)| e) + .collect(); + eliminate_mod = next_mod; + } + + let elf = elves[0]; + println!("Elf {} gets all the presents", elf); +} |