Refactor common code out

This commit is contained in:
2022-12-18 21:31:02 +01:00
parent 594226320d
commit 0c183b316e

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@@ -29,6 +29,22 @@ fn print_cavern(cavern: &IndexSet, max_height: usize) {
}
}
fn collides(shape: &[&[bool]], cavern: &IndexSet, x: usize, y: usize) -> bool {
for (row, line) in shape.iter().enumerate() {
if x + line.len() > WIDTH {
return true;
}
for (col, &on) in line.iter().enumerate() {
if on && cavern.contains((y - row) * WIDTH + x + col) {
return true;
}
}
}
false
}
pub fn part1(input: &[u8]) -> Result<String> {
// Poor man's trim()
let input = if input[input.len() - 1] == b'\n' {
@@ -50,25 +66,9 @@ pub fn part1(input: &[u8]) -> Result<String> {
let mut y = max_height + shape.len() + 2;
// Acquire gust of wind
'falling: for offset in gusts.by_ref() {
for offset in gusts.by_ref() {
if let Some(nx) = x.checked_add_signed(offset) {
let mut should_move = true;
'collision: for (row, line) in shape.iter().enumerate() {
if nx + line.len() > WIDTH {
should_move = false;
break 'collision;
}
for (col, &on) in line.iter().enumerate() {
if on && cavern.contains((y - row) * WIDTH + nx + col) {
should_move = false;
break 'collision;
}
}
}
if should_move {
if !collides(shape, &cavern, nx, y) {
x = nx;
}
} else {
@@ -76,19 +76,10 @@ pub fn part1(input: &[u8]) -> Result<String> {
}
// Move down if possible
if y >= shape.len() {
let ny = y - 1;
for (row, line) in shape.iter().enumerate() {
// No width check, should not hit that on the way down.
for (col, &on) in line.iter().enumerate() {
if on && cavern.contains((ny - row) * WIDTH + x + col) {
break 'falling;
}
}
}
y = ny;
if y >= shape.len() && !collides(shape, &cavern, x, y - 1) {
y -= 1;
} else {
break 'falling;
break;
}
}