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use std::{collections::HashMap};
use regex::Regex;
pub fn run(input: String) {
let lines: Vec<&str> = input.lines().collect();
let mut lix: usize = 0;
let mut ship: HashMap<usize, Vec<char>> = HashMap::new();
for line in lines.iter() {
lix += 1;
let chrs: Vec<char> = line.chars().collect();
// Line with just container numbers after the containers themselves
if chrs[1] == '1' {
break;
}
for (ix, container) in chrs.chunks(4).enumerate() {
let stack = ship.entry(ix+1).or_insert(Vec::new());// key starts at 1, of course
let payload = container[1];
if payload.is_alphabetic() {
stack.insert(0, payload) // last one we found is always the bottom of the stack
}
}
}
//println!("ship: {:?}", ship);
lix += 1;
let re = Regex::new(r"^move (\d+) from (\d+) to (\d+)$").unwrap();
assert!(re.is_match("move 1 from 2 to 4"));
for line in lines[lix..].iter() {
// parse the instruction...
// "move 1 from 2 to 1"
let mm = re.captures(line).expect("instruction didn't match regex???");
let n: usize = mm.get(1).unwrap().as_str().parse().unwrap();
let ifrom: usize = mm.get(2).unwrap().as_str().parse().unwrap();
let ito: usize = mm.get(3).unwrap().as_str().parse().unwrap();
//println!("moving {} from {} to {}", n, ifrom, ito);
// for _ in 0..n {
// let stackfrom = ship.get_mut(&ifrom).expect("couldn't find stack to pop from!");
// let ch = stackfrom.pop().expect("failed to pop from stack! maybe it was empty?");
// let stackto = ship.get_mut(&ito).expect("couldn't find stack to push to!");
// stackto.push(ch);
// }
let stackfrom = ship.get_mut(&ifrom).expect("couldn't find stack to pop from!");
let mut chunk: Vec<char> = Vec::new();
for _ in 0..n {
let ch = stackfrom.pop().expect("failed to pop from stack! maybe it was empty?");
chunk.push(ch);
}
let stackto = ship.get_mut(&ito).expect("couldn't find stack to push to!");
for _ in 0..n {
let ch = chunk.pop().unwrap();
stackto.push(ch);
}
}
print!("day 5: ");
for i in 1..(ship.keys().len()+1) {
let topch = ship.get(&i).unwrap().last().unwrap();
print!("{}", topch);
}
print!("\n");
}
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