86 lines
1.9 KiB
Rust
86 lines
1.9 KiB
Rust
#![feature(slice_split_once)]
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#![feature(test)]
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extern crate test;
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const INPUTS: [&[u8]; 2] = [
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include_bytes!("./sample.txt"),
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include_bytes!("./input.txt"),
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];
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fn process(data: &[u8]) -> u64 {
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let mut total = 0;
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for line in data.split(|&x| x == b'\n') {
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if line.is_empty() {
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continue;
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}
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let mut min_red = 0;
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let mut min_green = 0;
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let mut min_blue = 0;
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let line = &line[5..];
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let (_, mut line) = read_int(line);
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while !line.is_empty() {
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let (num, l) = read_int(&line[1..]);
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match l {
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[b'r', ..] => {
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min_red = min_red.max(num);
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line = &l[3..];
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}
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[b'g', ..] => {
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min_green = min_green.max(num);
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line = &l[5..];
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}
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[b'b', ..] => {
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min_blue = min_blue.max(num);
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line = &l[4..];
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}
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[b' ', ..] => line = l,
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_ => (),
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}
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}
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total += min_red * min_green * min_blue;
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}
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total
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}
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fn read_int(line: &[u8]) -> (u64, &[u8]) {
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let mut num = 0u64;
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let mut multiplier = 10_000u64;
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let mut ops_done = 0;
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for i in 0..line.len() {
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let c = line[i];
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if c.is_ascii_digit() {
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let c = line[i] - b'0';
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ops_done += 1;
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num += multiplier * c as u64;
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multiplier /= 10;
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} else if num != 0 {
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return (num / (10u64.pow(5 - ops_done)), &line[i + 1..]);
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} else {
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break;
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}
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}
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(num / (10u64.pow(5 - ops_done)), line)
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}
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fn main() {
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for input in INPUTS.iter() {
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println!("total = {}", process(input));
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}
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}
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#[bench]
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fn part2(b: &mut test::Bencher) {
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b.iter(|| {
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let v = process(INPUTS[1]);
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test::black_box(v);
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});
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}
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