2023-advent-of-code/src/05part2.rs

use std::fs;

fn main() {
    let file_path = "input/05input.txt";
    let contents = fs::read_to_string(file_path).expect("should read file");
    let mut lines = contents.lines();
    let seeds_str = lines.next().unwrap().strip_prefix("seeds: ").unwrap();
    let mut seeds: Vec<i128> = seeds_str.split(" ").map(|x| {x.parse::<i128>().ok().unwrap()}).collect();
    let mut soil = Vec::new();
    lines.next();
    lines.next();
    seeds = sort_by_pair(seeds);
    loop {
        let line = lines.next().unwrap();
        if line == "" {
            soil.append(&mut seeds);
            break;
        }
        process_line(line, &mut seeds, &mut soil);
    }
    soil = sort_by_pair(soil);
    let mut fertilizer = Vec::new();
    lines.next();
    loop {
        let line = lines.next().unwrap();
        if line == "" {
            fertilizer.append(&mut soil);
            break;
        }
        process_line(line, &mut soil, &mut fertilizer);
    }
    fertilizer = sort_by_pair(fertilizer);
    let mut water = Vec::new();
    lines.next();
    loop {
        let line = lines.next().unwrap();
        if line == "" {
            water.append(&mut fertilizer);
            break;
        }
        process_line(line, &mut fertilizer, &mut water);
    }
    water = sort_by_pair(water);
    let mut light = Vec::new();
    lines.next();
    loop {
        let line = lines.next().unwrap();
        if line == "" {
            light.append(&mut water);
            break;
        }
        process_line(line, &mut water, &mut light);
    }
    light = sort_by_pair(light);
    let mut temperature = Vec::new();
    lines.next();
    loop {
        let line = lines.next().unwrap();
        if line == "" {
            temperature.append(&mut light);
            break;
        }
        process_line(line, &mut light, &mut temperature);
    }
    temperature = sort_by_pair(temperature);
    let mut humidity = Vec::new();
    lines.next();
    loop {
        let line = lines.next().unwrap();
        if line == "" {
            humidity.append(&mut temperature);
            break;
        }
        process_line(line, &mut temperature, &mut humidity);
    }
    humidity = sort_by_pair(humidity);
    let mut location = Vec::new();
    lines.next();
    loop {
        match lines.next() {
            Some(line) => {
                process_line(line, &mut humidity, &mut location);
            },
            None => {
                location.append(&mut humidity);
                break;
            }
        }
    }
    location = sort_by_pair(location);
    println!("{:?}", location.first().unwrap());
}

fn range_from_line(line: &str) -> (i128, i128, i128) {
    let mut nums = line.split_whitespace();
    let dest = nums.next().unwrap().parse::<i128>().ok().unwrap();
    let source = nums.next().unwrap().parse::<i128>().ok().unwrap();
    let count = nums.next().unwrap().parse::<i128>().ok().unwrap();
    return (source, dest, count);
}

fn process_line(line: &str, input_vec: &mut Vec<i128>, out_vec: &mut Vec<i128>) {
    let values = range_from_line(line);
    let input_clone = input_vec.clone();
    let mut index = 0;
    for n in 0..input_clone.len()/2 {
        if input_clone[n*2] < values.0 + values.2 && input_clone[n*2] >= values.0 {
            out_vec.push(input_clone[n*2] - values.0 + values.1);
            if input_clone[n*2+1] <= values.2 - (input_clone[n*2] - values.0) {
                out_vec.push(input_clone[n*2+1]);
                input_vec.remove(index);
                input_vec.remove(index);
            } else {
                out_vec.push(values.2 - 1);
                input_vec.push(values.0 + values.2);
                input_vec.push(input_clone[n*2+1] - values.2 + 1);
                input_vec.remove(index);
                input_vec.remove(index);
            }
        } else if input_clone[n*2] < values.0 && input_clone[n*2] + input_clone[n*2+1] >= values.0 {
            out_vec.push(values.1);
            if input_clone[n*2] + input_clone[n*2+1] > values.0 + values.2 {
                out_vec.push(values.2 - 1);
                input_vec.push(input_clone[n*2]);
                input_vec.push(values.0 - input_clone[n*2]);
                input_vec.push(values.0 + values.2);
                input_vec.push(input_clone[n*2] + input_clone[n*2+1] - values.0 - values.2);
                input_vec.remove(index);
                input_vec.remove(index);
            } else {
                out_vec.push(input_clone[n*2] - values.0 + input_clone[n*2+1] - 1);
                input_vec.push(input_clone[n*2]);
                input_vec.push(values.0 - input_clone[n*2]);
                input_vec.remove(index);
                input_vec.remove(index);
            }
        } else if input_clone[n*2] + input_clone[n*2+1] < values.0 {
            index += 2;
        } else {
            break;
        }
    }
}

fn sort_by_pair(input_vec: Vec<i128>) -> Vec<i128> {
    let mut sort_vec = Vec::new();
    let mut out_vec = Vec::new();
    for i in 0..input_vec.len()/2 {
        if input_vec[i*2+1] == 0 {
            continue;
        }
        let insert_index: usize;
        match sort_vec.binary_search(&input_vec[i*2]) {
            Ok(val) => insert_index = val,
            Err(val) => insert_index = val,
        }
        sort_vec.insert(insert_index, input_vec[i*2]);
        out_vec.insert(insert_index * 2, input_vec[i*2]);
        out_vec.insert(insert_index*2+1, input_vec[i*2+1]);
    }
    return out_vec;
}