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#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_mut)]
use std::cmp::min;
use std::fs::File;
use std::io::Read;
#[derive(Debug)]
struct SeedMap {
dest: u64,
src: u64,
len: u64,
}
fn do_map(val: u64, sms: &Vec<SeedMap>) -> u64 {
for sm in sms.iter() {
if (sm.src <= val) && (val < sm.src + sm.len) {
return val + sm.dest - sm.src;
}
}
return val;
}
fn do_reverse_map(val: u64, sms: &Vec<SeedMap>) -> u64 {
for sm in sms.iter() {
if (sm.dest <= val) && (val < sm.dest + sm.len) {
return val + sm.src - sm.dest;
}
}
return val;
}
fn main() {
// let filename = "in/day05.ref";
let filename = "in/day05.pzl";
let mut f = File::open(filename).expect("cannot open file");
let mut content = String::new();
f.read_to_string(&mut content).expect("cannot read file");
let mut chunks = content.trim_end().split("\n\n");
// println!("{:?}", chunks);
let mut seeds: Vec<u64> = chunks
.next()
.unwrap()
.split_once(":")
.unwrap()
.1
.split(" ")
.filter_map(|x| x.parse().ok())
.collect::<Vec<u64>>();
let mut all_maps: Vec<Vec<SeedMap>> = Vec::new();
for chunk in chunks {
let mut chunk = chunk.split('\n');
let line = chunk.next();
let mut map_vec: Vec<SeedMap> = Vec::new();
for line in chunk {
let vals = line
.split(" ")
.filter_map(|x| x.parse().ok())
.collect::<Vec<u64>>();
map_vec.push(SeedMap {
dest: vals[0],
src: vals[1],
len: vals[2],
});
}
all_maps.push(map_vec);
}
let mut res1 = 999999999999;
for seed in seeds.clone().into_iter() {
res1 = min(res1, all_maps.iter().fold(seed, |s, m| do_map(s, m)));
}
let seed_pairs: Vec<_> = seeds
.chunks_exact(2)
.map(|x| (x[0] as u64, x[1] as u64))
.collect();
let mut res2 = 0;
for i in 0.. {
let a = all_maps.iter().rev().fold(i, |s, m| do_reverse_map(s, m));
if seed_pairs
.clone()
.into_iter()
.filter(|&(start, len)|
(start <= a) && (a < start + len))
.next()
.is_some()
{
res2 = i;
break;
}
}
println!("res1: {}", res1);
println!("res2: {}", res2);
assert_eq!(res1, 196167384);
assert_eq!(res2, 125742456);
}
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