day5: optimized

This commit is contained in:
Ishan Jain 2023-12-05 18:52:42 +05:30
parent dbe738c17e
commit 8b39941cb5
Signed by: ishan
GPG Key ID: 0506DB2A1CC75C27

View File

@ -1,4 +1,3 @@
#![feature(iter_array_chunks)]
#![feature(test)]
use std::ops::Range;
@ -20,13 +19,12 @@ fn process(data: &str) -> i64 {
.collect();
v.chunks(2)
.map(|x| (x[0]..x[0] + x[1]))
.map(|x| x[0]..x[0] + x[1])
.collect::<Vec<Range<i64>>>()
})
.unwrap();
let maps: Vec<Vec<(Range<i64>, Range<i64>)>> = lines
.map(|lines| {
let maps = lines.map(|lines| {
lines
.lines()
.skip(1)
@ -39,60 +37,62 @@ fn process(data: &str) -> i64 {
(y[1]..y[1] + size, y[0]..y[0] + size)
})
.collect()
})
.collect();
for map in maps {
let mut out = vec![];
.collect::<Vec<(Range<i64>, Range<i64>)>>()
});
for seed in seeds.drain(..) {
for map in maps {
let mut out = Vec::with_capacity(seeds.len());
for seed in seeds {
// split seed based on this rangemap
let splitted = split(&map, seed);
out.extend(splitted);
}
seeds.extend_from_slice(&out);
seeds = out
}
seeds.into_iter().map(|x| x.start).min().unwrap()
}
fn split(map: &[(Range<i64>, Range<i64>)], node: Range<i64>) -> Vec<Range<i64>> {
let mut out = vec![];
let mut out = Vec::with_capacity(map.len());
let mut stack = vec![node];
while let Some(node) = stack.pop() {
let mut found_match = false;
for (src, dst) in map.iter() {
for (src, dst) in map
.iter()
.skip_while(|(src, _)| node.end.min(src.end) - node.start.max(src.start) <= 0)
{
let overlap = std::cmp::max(0, node.end.min(src.end) - node.start.max(src.start));
if overlap <= 0 {
break;
}
if overlap == 0 {
continue;
} else if node.start > src.start && node.end < src.end {
let dst = if node.start == src.start && node.end == src.end {
dst.clone()
} else if node.start >= src.start && node.end <= src.end {
// src engulfs node
let offset = std::cmp::max(0, node.start - src.start);
let dst = dst.start + offset..dst.start + offset + overlap;
found_match = true;
out.push(dst);
dst.start + offset..dst.start + offset + overlap
} else if node.start < src.start && node.end > src.end {
// node engulfs src
let r1_non = node.start..src.start;
let r2_non = src.end..node.end;
found_match = true;
stack.extend([r1_non, r2_non]);
out.push(dst.clone());
stack.push(r1_non);
stack.push(r2_non);
dst.clone()
} else {
// Partial overlap
let offset = std::cmp::max(0, node.start - src.start);
let dst_range = dst.start + offset..dst.start + offset + overlap;
found_match = true;
let new_range = if node.start < src.start {
node.start..src.start
} else {
@ -100,8 +100,11 @@ fn split(map: &[(Range<i64>, Range<i64>)], node: Range<i64>) -> Vec<Range<i64>>
};
stack.push(new_range);
out.push(dst_range);
}
dst_range
};
found_match = true;
out.push(dst);
}
if !found_match {
@ -114,12 +117,12 @@ fn split(map: &[(Range<i64>, Range<i64>)], node: Range<i64>) -> Vec<Range<i64>>
fn main() {
for input in INPUTS.iter() {
println!("total = {}", process(input));
println!("answer = {}", process(input));
}
}
#[bench]
fn part1(b: &mut test::Bencher) {
fn part2(b: &mut test::Bencher) {
b.iter(|| {
let v = process(INPUTS[1]);
test::black_box(v);