World interpretation rust

world_interpretation.rs

use std::collections::HashMap;

#[derive(Debug,Hash,PartialEq,Eq,Copy,Clone)]
struct Pos(i8, i8);

type CharMat = Vec<Vec<char>>;
type MemoHash = HashMap<String, usize>;

struct Maze {
  mat: CharMat,
  origin: Pos,
  keys_len: usize,
  memo: MemoHash,
  usage: usize,
  actual: usize
}

impl Maze {
  fn new(strs: &str) -> Maze {
    let mat = strs.lines()
      .map(String::from)
      .map(|l| l.chars().collect())
      .collect::<CharMat>();
      
    let mut origin = Pos(0,0);
    let mut keys_len = 0;
      
    for (i, line) in mat.iter().enumerate() {
      if let Some(j) = line.iter()
        .position(|&c| c == '@')
      {
        origin = Pos(i as i8, j as i8)
      }
      keys_len = keys_len + line.iter()
        .filter(|&c| c.is_lowercase()).count();
    }
      
    Maze {
      mat,
      origin,
      keys_len,
      memo: HashMap::new(),
      usage: 0,
      actual: 0
    }
  }
    
  fn char(&self, p: &Pos) -> char {
    self.mat[p.0 as usize][p.1 as usize]
  }
  
  fn locate_keys(
    &self, p: &Pos, keys: &Vec<char>
  ) -> Vec<(char, Pos, usize)> {
    let dirs: [(i8,i8);4] = 
      [(-1,0), (0,1), (1,0), (0,-1)];
    let mut marked: HashMap<Pos, bool> = 
      HashMap::new();
    let mut queue: Vec<(Pos, usize)> = 
      vec![(p.clone(), 0)];
    let mut dest = vec![];
    let mut i = 0;
    
    loop {
      if i == queue.len() { break; }
      let (p, dist) = queue[i];
      i = i + 1;
      marked.insert(p.clone(), true);
      
      let c = self.char(&p);
      let key_taken = keys.iter()
        .find(|&&k| k == c) != None;
//    println!("{:?}:{}, {}", p, c, key_taken);
      
      if c.is_lowercase() && !key_taken { 
        dest.push((c, p.clone(), dist));
      } else {
        for d in dirs.iter() {
          let q = Pos(d.0+p.0, d.1+p.1);
          if marked.get(&q) != None { continue }
          
          let qc = self.char(&q);
          if qc == '#' { continue }
          
          if qc.is_uppercase() {
            let door_key = qc.to_ascii_lowercase();
            let key_found = keys.iter()
              .find(|&&k| k == door_key) != None;
            if !key_found { continue }
          }
          queue.push((q, dist+1));
        }
      }
    }
    
    dest
  }
  
  fn memo_key<'a>(
    p: &'a Pos, keys: &'a Vec<char>
  ) -> String {
    let mut ordered = keys.clone();
    ordered.sort();
    let s: String = ordered.into_iter().collect();
    format!("{}:({},{})", s, p.0, p.1)
  }
  
  fn min_steps(
    &mut self, p: &Pos, keys: &Vec<char>
  ) -> usize {
    let mut steps = 100000;
    let mkey = Maze::memo_key(&p, &keys);
    if let Some(msteps) = self.memo.get(&mkey) {
      steps = *msteps
    } else {
      if keys.len() == self.keys_len {
        steps = 0
      } else {
        let keys_found = self.locate_keys(p, keys);
        for (qc, q, qdist) in keys_found.iter() {
          let mut qkeys = keys.clone();
          qkeys.push(qc.clone());
          let qsteps = self.min_steps(&q, &qkeys)+qdist;
          //      println!("{} {:?} {}", qc, q, qdist);
          if qsteps < steps { steps = qsteps; }
        }
      }
      self.memo.insert(mkey, steps);
      self.actual += 1;
    }
    
    self.usage += 1;
    steps
  }
  
  fn solve(&mut self) -> usize {
    let o = self.origin.clone();
    let res = self.min_steps(&o, &vec![]);
    println!("usage: {} {}", self.usage, self.actual);
    res
  }
}

fn main() {
  let mut w1 = Maze::new("\
#########
#b.A.@.a#
#########"
  );
  println!("{}", w1.solve());

  let mut w2 = Maze::new("\
########################
#f.D.E.e.C.b.A.@.a.B.c.#
######################.#
#d.....................#
########################"
  );
  println!("{}", w2.solve());

  let mut w3 = Maze::new("\
#################
#i.G..c...e..H.p#
########.########
#j.A..b...f..D.o#
########@########
#k.E..a...g..B.n#
########.########
#l.F..d...h..C.m#
#################"
  );
  println!("{}", w3.solve());
  
  let mut w4 = Maze::new("\
########################
#@..............ac.GI.b#
###d#e#f################
###A#B#C################
###g#h#i################
########################"
  );
  println!("{}", w4.solve());
  
  let mut w5 = Maze::new("\
#################################################################################
#.....#.....#z#...C.....#.........#.....#.#.....#.......V.#.....#.........#b....#
###.#.###.#.#.#.#####.###.#.#######.###.#.#.#.#.#.#######.#####.#.#######.#.#.###
#...#..y..#.#.#.#...#.#...#........p#...#...#.#...#.....#.#...T.#...#...#...#...#
#.#.#######.#.#.#.###.#.#############.#.#####.#####.#####.#.#.###.###.#.#.#####H#
#.#.#.....#.#.#.#...#...#..l....#.....#.#...Y.#...#.......#.#.#...#...#.#.....#.#
#.#.#.###.#.#.#.###.#####.###.###.#####.#.#####.###.#######.###.###.###.#######.#
#.#.#.G.#.#...#...#.........#...#.#.....#.#...#...#.#.#.........#...#.#...#.....#
#.#####.#.#######.#############.#.#####.#.#.###.#.#.#.#.#####.###.###.###.#.###.#
#.....#.#.......#.........#.....#.....#.#.#.#...#...#...#...#...#.#.......#...#.#
#.#.#.#.#######.#########.#.###.#####.###.#.#.###########.#.###.#.###.#######.#.#
#.#.#.#.#.....#.....#...#...#.#.#...#...#.#...............#...#.#...#.........#.#
###.###.###.#.###.###.#.#####.#.#.#####.#.###################.#####.###########.#
#...#...#...#.#...#...#...#...#...#.....#...#...#...........#.....#.#..g..#...#.#
#A###.###.###.#.#.#.###.###.#.###.#.###.###Z#.#.#.#########.#####.#.#.###.#.#.#.#
#...#...#.#...#.#.#.#.#.....#.....#.#.#.#.#...#..n#.......#.....#i..#...#...#.#.#
#.#.###.#.#.###.###.#.#############.#.#.#.#########.#.#########N#######.#####.#.#
#.#...#...#...#.#.......#...........#.#.#.#.X.....#.#.#.......#....o#.#.#...#.#.#
#.###.#######.#.#.#######.###########.#.#.#.###.###.#.#.#####.#####.#.#.###.#.#.#
#v#.#.#.....#.#...#.....#.......#.#.....#.#...#..u..#.#.#e....O...#.#.#.#...#...#
#.#.#.#.###.#.#####.###.#.#####.#.#.#####.###.#######.#.###.#####.#.#.#W#.#.#####
#...#.#...#.#.#.#...#...#.....#.#.#.#...#.........#...#...#.#.#.#.#.#.#...#.#...#
#####.#.###.#.#.#.#######.#####.#.#.###.#.#########.#####.###.#.#.#.#.#####.#.###
#.....#.#...#...#.#.......#.....#.#.....#.....#...#.#.....#...#.....#.....#.#...#
#.#####.#.#####.#.###.#####.#####.#####.#####.#.#.#.#.###.#D#########.#####.###.#
#.I.#...#.....#.#...#...#...#.......#...#.K.#.#.#...#q..#.#.#......d#.....#...#.#
#.#.#.#####.#.#.###.#####.###.###.###.#####.#.#.#######.#E#.#.#####.###.#.###.#.#
#.#.#.#...#.#...#...#...#...#...#.....#.#...#.#.......#.#.#...#...#.R.#.#...#.#.#
#.#.#.#.#.#######.###.#.###.###.#######.#.###.#####.###.#######.#####.#.#.###.#.#
#.#...#.#.........#...#.....#.....#...#.#...#.#...#...#.....#r..#.....#.#.#...#.#
#######.###########.#############.#.#.#.###.#.#.#.###.###.#.#.#.#.#####.#.#.###.#
#w..#...#.........#.....#.....#...#.#...#...#.#.#.....#.#.#.#.#.#.#...#.#...#...#
#.#.#.###.#######.###.#.#.###.#.###.###.#.###.#.#####.#.#.###Q#.#.###.#.#####.#.#
#.#.#.....#.....#...#.#.....#.#.....#.#.#...#.#...#.....#.....#...#...#.......#.#
#.#.#######.###.###.#.#######.#######.#.#.#.#.###.#####.###########.#.#########.#
#.#.#.......#.#...#.#.#.....#...#.....#.#.#.#...#...#.....J.........#...#...#...#
#.#.#.#######.#.###.###.###.###.#.###.#.#.#.###.###.###############.#####.#.#.###
#.#...#...#...#.....#...#.#.....#.#.#...#.#.....#.#.......#...#...#.#...#.#.#.#.#
#.#####.#.#.#.#######.###.#######.#.#####.#######.#######.#.#.#.#.###.#.#.#.#.#.#
#.......#...#.........#.................................#...#...#.....#...#.....#
#######################################.@.#######################################
#.....#.......#.#.........#...#...#...#...........#.........#...................#
#.###.#.#####.#.#.#####.#.#.#.#.#.#.#.#.#.#.#######.#######.#.#####.#######.###.#
#...#...#...#...#.#...#.#...#...#...#...#.#.#...#...#...#.#...#...#.#.....#.#...#
#.#.###.#.#.#####.#.#.#.#####.#########.#.#.#.#.#.###.#.#.#####.#.#.#.#####.#.###
#.#...#.#.#.......#.#.#.#.....#.......#.#.#.#.#...#...#...#...#.#.#...#...#.#.#.#
#.###.###.###########.#.#.#####.#####.###.#.#.#####.#######.#.#.#.#####.#.#.#.#.#
#...#...#.#.......#...#.#.#.#...#...#...#.#...#.....#.......#...#...#...#.#.#.#.#
###.###.#.#####.#.#.###.#.#.#.###.#.#.#.#.#####.#####.#############.#.###.#.#.#.#
#.#.#.#.........#.#...#.#...#.#...#.#.#.#.#.........#.....#.......#...#.#...#..m#
#.#.#.###########.###.#.###.#.#.###.###.#.###.#####.#####.#.#####.#####.###.#####
#...#.#.....#...#.#...#.#...#.#.#.#...#.#k..#.#.......#...#.#...#...#.......#...#
#.###.#.###.#.###.#.###.#.###.#.#.###.#.###.#.#.#####.#.###.#.#.###.###.#####.#.#
#...#j#.#.#.#.#...#.#...#.#...#.#.#...#.#...#.#.#.....#.......#...#...#.#...S.#.#
###.#.#.#.#.#.#.###.#.#####.###.#.#.###.#.#####.#.#############.#####.###.#####.#
#.#...#.#.#.#.......#.......#...#.#.#...#.......#.#...#...#.....#.....#...#...#.#
#.###.#.#.#.#######.#########.###.#.#.#.###.#######.#.#.#.###.###.#.###.#####.#.#
#.....#...#...#.M.........#...#.....#.#.#...#.......#...#...#...#.#.#...#.....#.#
#.#######.###.#.#####.#####.###.#####.#.#.###.#############.#####.###.###.#####.#
#...#.#...#.#.#.#...#.#...#.#.........#.#.#.#.....#.......#....a#...#.#...#...#.#
###.#.#.###.#.###.#.###.#.#.###########.#.#.#####.#.#####.#####.#.#.#.#.###.#.#.#
#.#...#....t#.....#.#.#.#.#...........#.#...#...#.#.....#...#...#.#...#.#...#...#
#.###.#####.#######.#.#.#.#.#########.#.###.###.#.#.###.#########.#####.#.#####.#
#.#...#...#.#...#.#...#.#.#...#.....#.#.#.#...#.#.#...#...#.....#...#...#.#...#.#
#.#.###.#.#.#.#.#.#####.#.###.#.#####.#.#.###.#.#.###.###.#.#.#####.###.#.#.#.#.#
#...#.#.#...#.#.....#...#.#...#.#.....#.#...#.#.#...#...#.#.#.#.........#.#.#.#.#
#.###.#.#####.#####.###.#.#.###.#.#####.#.#.#.#.###.###.#.#.#.#.#########.#.###.#
#.....#.#.........#.....#.#.....#...#...#.#.#x#...#.#...#...#...#.........#..f#.#
#####.#.#####.###.#######.#####.###.#.#####.#.#.#.#.#####.#######.#########.#.#.#
#.#...#.#...#.#...#...#...#.....#.#.#...#...#.#.#.#.#...#...L...#.#.......#.#...#
#.#.###.#.#.###.###.#.#.###.#####.#.#####.###.###.#.#B#.#########.###.###.#.#####
#.#.P.#...#.....#.#.#.#...#.......#.....#...#.....#...#.........#...#...#.....#.#
#.###.###########.#.#.###.#############.###.#####.#############.###.#.#######.#.#
#c....#...#.#.......#...#.#.......#...#.#.....#...#...#.....#.#.#...#.#...#.....#
#.#####.#.#.#.#######.###.#.#####.#.#.#.#.#.###.###.#.#.#.#.#.#.#.#####.#.#####.#
#...#..s#.#.F.....#...#...#.#...#.#.#...#.#.#...#...#...#.#.#.#.#.......#.....#.#
###.###.#.#######.#.#.#.###.#.###.#.###.#.###.###########.#.#.#.#####.#######.###
#...#...#.#...#...#.#.#...#.#...#...#.#.#.....#.......#...#...#.#...#.#.....#...#
#.###.###.#.#.#####.#.###.#.#.#.#####.#.#.#######.###.#.#####.#.#.#.###.###.###.#
#.....#.....#.......#...#...#.#.........#.....U...#.....#.....#...#....h#.......#
#################################################################################"
  );
  println!("{}", w5.solve());
}