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use advent_lib::prelude::*;
use std::collections::BTreeMap;
fn main() -> Result<()> {
let args = std::env::args();
if args.len() != 1 {
eprintln!("Usage: advent");
}
let starting_numbers = vec![2, 15, 0, 9, 1, 20];
let mut history: BTreeMap<usize, usize> = BTreeMap::new();
let mut output = 0;
let mut next_output = 0;
for i in 0 .. starting_numbers.len() {
output = starting_numbers[i];
next_output = match history.get(&output) {
Some(previous) => i - previous,
None => 0,
};
history.insert(output, i);
}
for i in starting_numbers.len() .. 2020 {
output = next_output;
next_output = match history.get(&output) {
Some(previous) => i - previous,
None => 0,
};
history.insert(output, i);
}
println!("{}", output);
for i in 2020 .. 30000000 {
output = next_output;
next_output = match history.get(&output) {
Some(previous) => i - previous,
None => 0,
};
history.insert(output, i);
}
println!("{}", output);
Ok(())
}
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