use std::io; use std::io::{BufRead, Write}; use std::ops::{Rem, Div, Mul}; use std::collections::vec_deque::VecDeque; use std::cmp::min; macro_rules! input { (source = $s:expr, $($r:tt)*) => { let mut iter = $s.split_whitespace(); input_inner!{iter, $($r)*} }; (stdin = $s:expr, $($r:tt)*) => { let s = { let mut s = String::new(); $s.read_to_string(&mut s).unwrap(); s }; let mut iter = s.split_whitespace(); input_inner!{iter, $($r)*} }; } macro_rules! input_inner { ($iter:expr) => {}; ($iter:expr, ) => {}; ($iter:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($iter, $t); input_inner!{$iter $($r)*} }; } macro_rules! read_value { ($iter:expr, ( $($t:tt),* )) => { ( $(read_value!($iter, $t)),* ) }; ($iter:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($iter, $t)).collect::>() }; ($iter:expr, chars) => { read_value!($iter, String).chars().collect::>() }; ($iter:expr, usize1) => { read_value!($iter, usize) - 1 }; ($iter:expr, $t:ty) => { $iter.next().unwrap().parse::<$t>().expect("Parse error") }; } #[allow(unused_macros)] macro_rules! assert_judge { ($method:ident, $input:expr, $expected:expr) => { { let input = $input.as_bytes(); let mut output = Vec::new(); $method(&input[..], &mut output); let output = String::from_utf8(output).expect("Not UTF-8"); assert_eq!($expected, output); } }; } #[allow(unused_macros)] macro_rules! assert_judge_with_output { ($method:ident, $input:expr) => { { let input = $input.as_bytes(); let mut output = Vec::new(); $method(&input[..], &mut output); String::from_utf8(output).expect("Not UTF-8") } }; } #[allow(unused_macros)] macro_rules! assert_eq_with_error { ($left:expr, $right:expr, $precision:expr) => ({ match (&$left, &$right, &$precision) { (left_val, right_val, precision_val) => { if !(*left_val - *precision_val < *right_val && *right_val < *left_val + *precision_val) { // The reborrows below are intentional. Without them, the stack slot for the // borrow is initialized even before the values are compared, leading to a // noticeable slow down. panic!(r#"assertion failed: `(left == right) +- precision` left: `{:?}`, right: `{:?}`, precision: `{:?}`"#, &*left_val, &*right_val, &*precision_val) } } } }); } trait GenericInteger: Copy + PartialEq + Rem + Div + Mul { fn zero() -> Self; } macro_rules! dec_gi { () => {}; ($t:ty $(, $r:ty)*) => { impl GenericInteger for $t { fn zero() -> Self { 0 } } dec_gi![ $( $r ),* ]; }; } dec_gi![u8, u16, u32, u64, u128, usize, i8, i16, i32, i64, i128, isize]; #[allow(dead_code)] fn gcd(a: T, b: T) -> T where T: GenericInteger { if b == T::zero() { a } else { gcd(b, a % b) } } #[allow(dead_code)] fn lcm(a: T, b: T) -> T where T: GenericInteger { a / gcd(a, b) * b } fn main() { let stdio = io::stdin(); let input = stdio.lock(); let output = io::stdout(); process(input, output); } fn process(mut reader: R, mut writer: W) -> () where R: BufRead, W: Write { input! { stdin = reader, w: usize, h: usize, c: [chars; h] } // // find first hole // let mut i = c.iter().position(|r| r.iter().find(|&c| *c == '.').is_some()).unwrap(); // let mut j = c[i].iter().position(|c| *c == '.').unwrap(); // let mut first_hole = vec![(i, j)]; // loop { // if c[i][j + 1] == '.' { // first_hole.push((i, j + 1)); // j = j + 1; // } else { // loop { // // } // } // } // // write!(writer, "{}", i); // checked editor's note :( #[derive(Debug, Clone)] struct Point { x: usize, y: usize, } // c[y][x] let y = c.iter().position(|r| r.iter().find(|&c| *c == '.').is_some()).unwrap(); let x = c[y].iter().position(|c| *c == '.').unwrap(); const MAX_SIZE: usize = 21; let mut checked = [[false; MAX_SIZE]; MAX_SIZE]; for i in 0..y { for j in 0..MAX_SIZE { checked[i][j] = true; } } for j in 0..=x { checked[y][j] = true; } for i in 0..MAX_SIZE { checked[i][0] = true; checked[i][MAX_SIZE - 1] = true; } for j in 0..MAX_SIZE { checked[0][j] = true; checked[MAX_SIZE - 1][j] = true; } let mut first_hole = vec![Point { x, y }]; let mut search_queue = VecDeque::new(); search_queue.push_back((y + 1, x)); checked[y + 1][x] = true; search_queue.push_back((y, x + 1)); checked[y][x + 1] = true; while let Some((y, x)) = search_queue.pop_front() { if c[y][x] == '.' { first_hole.push(Point { x, y }); if !checked[y + 1][x] { search_queue.push_back((y + 1, x)); checked[y + 1][x] = true; } if !checked[y - 1][x] { search_queue.push_back((y - 1, x)); checked[y - 1][x] = true; } if !checked[y][x + 1] { search_queue.push_back((y, x + 1)); checked[y][x + 1] = true; } if !checked[y][x - 1] { search_queue.push_back((y, x - 1)); checked[y][x - 1] = true; } } } let first_y = y; let mut x = 0; let mut y = 0; 'outer: for (i, r) in c.iter().skip(first_y - 1).enumerate() { for (j, c) in r.iter().enumerate() { if !checked[i][j] && *c == '.' { y = i; x = j; break 'outer; } } } for i in 0..y { for j in 0..MAX_SIZE { checked[i][j] = true; } } for j in 0..=x { checked[y][j] = true; } let mut second_hole = vec![Point { x, y }]; if !checked[y + 1][x] { search_queue.push_back((y + 1, x)); checked[y + 1][x] = true; } if !checked[y][x + 1] { search_queue.push_back((y, x + 1)); checked[y][x + 1] = true; } while let Some((y, x)) = search_queue.pop_front() { if c[y][x] == '.' { second_hole.push(Point { x, y }); if !checked[y + 1][x] { search_queue.push_back((y + 1, x)); checked[y + 1][x] = true; } if !checked[y - 1][x] { search_queue.push_back((y - 1, x)); checked[y - 1][x] = true; } if !checked[y][x + 1] { search_queue.push_back((y, x + 1)); checked[y][x + 1] = true; } if !checked[y][x - 1] { search_queue.push_back((y, x - 1)); checked[y][x - 1] = true; } } } let mut min_distance = std::i32::MAX; for Point { x: x1, y: y1 } in first_hole { for Point { x: x2, y: y2 } in &second_hole { min_distance = min(min_distance, (*x2 as i32 - x1 as i32).abs() + (*y2 as i32 - y1 as i32).abs() - 1); } } write!(writer, "{}", min_distance); } #[cfg(test)] mod tests { use super::*; #[test] fn sample1() { assert_judge!(process, " 9 5 ######### #.####.## #..###.## #..###..# ######### ", "3"); } #[test] fn sample2() { assert_judge!(process, " 8 5 ######## ####..## #..#..## #...#### ######## ", "1"); } #[test] fn sample3() { assert_judge!(process, " 9 9 ######### #.......# #.#####.# #.#...#.# #.#.#.#.# #.#...#.# #.#####.# #.......# ######### ", "1"); } #[test] fn sample4() { assert_judge!(process, " 8 6 ######## #....### #.###### #.####.# #.###### ######## ", "3"); } }