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Clean up Day 21

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This commit is contained in:
Christian
2023-12-28 14:04:04 +01:00
parent 9c4e8e8774
commit dc477f4282
1 changed files with 8 additions and 8 deletions
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16
src/bin/day21.rs
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@@ -106,18 +106,18 @@ fn bfs(plot: &Plot) -> Vec<u64> {
distance += 1; distance += 1;
} }
return distances; distances
} }
fn interpolate(x0: usize, mut ys: [i64; 4], x: usize) -> Option<i64> { fn interpolate(x0: usize, mut ys: [i64; 4], x: usize) -> Option<i64> {
assert!(x >= x0); assert!(x >= x0);
if x <= x0 + 3 { if x <= x0 + 3 {
Some(ys[(x - x0) as usize]) Some(ys[x - x0])
} else { } else {
let mut f = [0; 4]; let mut f = [0; 4];
for i in 0..4 { for coef in &mut f {
f[i] = ys[0]; *coef = ys[0];
for i in 0..ys.len() - 1 { for i in 0..ys.len() - 1 {
ys[i] = ys[i + 1] - ys[i]; ys[i] = ys[i + 1] - ys[i];
} }
@@ -125,7 +125,7 @@ fn interpolate(x0: usize, mut ys: [i64; 4], x: usize) -> Option<i64> {
let xa = (x - x0) as i64; let xa = (x - x0) as i64;
let xb = xa * (x - x0 - 1) as i64; let xb = xa * (x - x0 - 1) as i64;
(f[3] == 0).then_some(f[0] + f[1] * xa as i64 + f[2] * xb / 2) (f[3] == 0).then_some(f[0] + f[1] * xa + f[2] * xb / 2)
} }
} }
@@ -153,7 +153,7 @@ fn main() -> Result<()> {
assert!(plot.height == plot.width); assert!(plot.height == plot.width);
let side_length = width; let side_length = width;
let required_scale = let required_scale =
|step_count| (step_count - plot.start.0 as usize + side_length) / side_length; |step_count| (step_count - plot.start.0 + side_length) / side_length;
let offset = STEPS_P2 % side_length; let offset = STEPS_P2 % side_length;
let max_scale = required_scale(STEPS_P2); let max_scale = required_scale(STEPS_P2);
@@ -168,8 +168,8 @@ fn main() -> Result<()> {
plot.scale_to(scale0 + 3); plot.scale_to(scale0 + 3);
let distances = bfs(&plot); let distances = bfs(&plot);
for i in 0..4 { for (i, seq) in sequence.iter_mut().enumerate() {
sequence[i] = positions(&distances, (offset + i * side_length) as u64) as i64; *seq = positions(&distances, (offset + i * side_length) as u64) as i64;
} }
let mut n = 0; let mut n = 0;