63 lines
1.3 KiB
Rust
63 lines
1.3 KiB
Rust
fn merge_layers(layers: &[&[u8]]) -> Vec<u8> {
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let mut image = Vec::new();
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image.resize(layers[0].len(), 2);
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for layer in layers {
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for (ndx, b) in layer.into_iter().enumerate() {
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let digit = *b - b'0';
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if image[ndx] != 2 { continue; }
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image[ndx] = digit;
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}
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}
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image
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}
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fn split_layers(input: &[u8], image_size: usize) -> Vec<&[u8]> {
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assert_eq!(input.len() % image_size, 0);
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input.chunks(image_size).collect::<Vec<_>>()
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}
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fn main() {
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let input = include_bytes!("input.txt");
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let layers = split_layers(input, 6*25);
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let min0_product12 = layers.iter().map(|layer| {
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let mut count = [0, 0, 0];
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for b in *layer {
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let digit = *b - b'0';
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if digit < 3 {
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count[digit as usize] += 1;
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}
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}
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(count[0], count[1]*count[2])
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}).min_by_key(|(zeroes, _product12)| *zeroes).unwrap().1;
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println!("Product of counts of 1 and 2 for the layer with min 0s: {}", min0_product12);
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let image = merge_layers(&layers);
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for row in image.chunks(25) {
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for cell in row {
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match cell {
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1 => print!("#"),
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_ => print!(" "),
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}
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}
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println!("");
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}
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}
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#[cfg(test)]
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mod day8test {
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use super::*;
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#[test]
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fn examples1() {
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// no runnable examples
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}
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#[test]
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fn examples2() {
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let layers = split_layers(b"0222112222120000", 4);
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assert_eq!(merge_layers(&layers), [0, 1, 1, 0]);
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}
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}
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