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2021: day04: better Iterator return type

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This commit is contained in:
Antoine Martin 2021-12-04 15:18:38 +01:00
parent 45c3426537
commit 6dccc14046
1 changed files with 4 additions and 4 deletions
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8
aoc2021/src/day04.rs
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@ -46,7 +46,7 @@ fn part1(input: &str) -> Result<u64> {
match (wdraw, wgrid) { match (wdraw, wgrid) {
(Some(draw), Some(grid)) => { (Some(draw), Some(grid)) => {
Ok(draw as u64 * grid.unmarked_numbers().map(|n| *n as u64).sum::<u64>()) Ok(draw as u64 * grid.unmarked_numbers().map(|n| n as u64).sum::<u64>())
} }
_ => Err(anyhow!("couldn't find a winning grid!")), _ => Err(anyhow!("couldn't find a winning grid!")),
} }
@ -89,7 +89,7 @@ fn part2(input: &str) -> Result<u64> {
for draw in draws { for draw in draws {
if last_grid.mark(draw) { if last_grid.mark(draw) {
return Ok(draw as u64 * last_grid.unmarked_numbers().map(|n| *n as u64).sum::<u64>()); return Ok(draw as u64 * last_grid.unmarked_numbers().map(|n| n as u64).sum::<u64>());
} }
} }
@ -120,10 +120,10 @@ impl Grid {
} }
} }
fn unmarked_numbers(&self) -> impl Iterator<Item = &u8> { fn unmarked_numbers(&self) -> impl Iterator<Item = u8> + '_ {
self.number_to_pos self.number_to_pos
.iter() .iter()
.filter_map(|(num, &(x, y))| (!self.access_grid(x, y)).then(|| num)) .filter_map(|(num, &(x, y))| (!self.access_grid(x, y)).then(|| *num))
} }
fn access_grid(&self, x: usize, y: usize) -> bool { fn access_grid(&self, x: usize, y: usize) -> bool {