Problem:
Score : 300 points

Problem Statement

There is a grid with H rows and W columns, where each square is painted black or white.

You are given H strings S_1, S_2, ..., S_H, each of length W.
If the square at the i-th row from the top and the j-th column from the left is painted black, the j-th character in the string S_i is #; if that square is painted white, the j-th character in the string S_i is ..

Find the number of pairs of a black square c_1 and a white square c_2 that satisfy the following condition:

There is a path from the square c_1 to the square c_2 where we repeatedly move to a vertically or horizontally adjacent square through an alternating sequence of black and white squares: black, white, black, white...

Constraints

1 \leq H, W \leq 400

|S_i| = W (1 \leq i \leq H)

For each i (1 \leq i \leq H), the string S_i consists of characters # and ..

Input

Input is given from Standard Input in the following format:

H W
S_1
S_2
:
S_H

Output

Print the answer.

Sample Input 1

3 3
.#.
..#
#..

Sample Output 1

10

Some of the pairs satisfying the condition are ((1, 2), (3, 3)) and ((3, 1), (3, 2)), where (i, j) denotes the square at the i-th row from the top and the j-th column from the left.

Sample Input 2

2 4
....
....

Sample Output 2

0

Sample Input 3

4 3
###
###
...
###

Sample Output 3

6

Solution in Rust (1.15.1) (judge verdict: Time Limit Exceeded)

#[allow(unused_imports)]
use std::cmp::{max, min, Ordering};
#[allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
#[allow(unused_imports)]
use std::io::{stdin, stdout, BufWriter, StdoutLock, Write};
#[allow(unused_imports)]
use std::iter::FromIterator;
#[allow(unused_macros)]
macro_rules ! input { ( source = $ s : expr , $ ( $ r : tt ) * ) => { let mut iter = $ s . split_whitespace ( ) ; let mut next = || { iter . next ( ) . unwrap ( ) } ; input_inner ! { next , $ ( $ r ) * } } ; ( $ ( $ r : tt ) * ) => { let stdin = std :: io :: stdin ( ) ; let mut bytes = std :: io :: Read :: bytes ( std :: io :: BufReader :: new ( stdin . lock ( ) ) ) ; let mut next = move || -> String { bytes . by_ref ( ) . map ( | r | r . unwrap ( ) as char ) . skip_while ( | c | c . is_whitespace ( ) ) . take_while ( | c |! c . is_whitespace ( ) ) . collect ( ) } ; input_inner ! { next , $ ( $ r ) * } } ; }
#[allow(unused_macros)]
macro_rules ! input_inner { ( $ next : expr ) => { } ; ( $ next : expr , ) => { } ; ( $ next : expr , $ var : ident : $ t : tt $ ( $ r : tt ) * ) => { let $ var = read_value ! ( $ next , $ t ) ; input_inner ! { $ next $ ( $ r ) * } } ; }
#[allow(unused_macros)]
macro_rules ! read_value { ( $ next : expr , ( $ ( $ t : tt ) ,* ) ) => { ( $ ( read_value ! ( $ next , $ t ) ) ,* ) } ; ( $ next : expr , [ $ t : tt ; $ len : expr ] ) => { ( 0 ..$ len ) . map ( | _ | read_value ! ( $ next , $ t ) ) . collect ::< Vec < _ >> ( ) } ; ( $ next : expr , chars ) => { read_value ! ( $ next , String ) . chars ( ) . collect ::< Vec < char >> ( ) } ; ( $ next : expr , bytes ) => { read_value ! ( $ next , String ) . into_bytes ( ) } ; ( $ next : expr , usize1 ) => { read_value ! ( $ next , usize ) - 1 } ; ( $ next : expr , $ t : ty ) => { $ next ( ) . parse ::<$ t > ( ) . expect ( "Parse error" ) } ; }
#[allow(dead_code)]
pub fn with_bufwriter<F: FnOnce(BufWriter<StdoutLock>) -> ()>(f: F) {
    let out = stdout();
    let writer = BufWriter::new(out.lock());
    f(writer)
}
#[allow(unused_macros)]
macro_rules ! debug { ( $ ( $ a : expr ) ,* ) => { eprintln ! ( concat ! ( $ ( stringify ! ( $ a ) , " = {:?}, " ) ,* ) , $ ( $ a ) ,* ) } ; }
#[allow(dead_code)]
fn main() {
    input!{
        h: usize,
        w: usize,
        s: [chars; h],
    }
    let dx = [1, 0, -1, 0];
    let dy = [0, 1, 0, -1];
    let mut ans: u64 = 0;
    for sx in 0..h {
        for sy in 0..w {
            if s[sx][sy] != '#' {
                continue;
            }
            let mut white = true;
            let mut visited = vec![vec![false; w]; h];
            let mut q: VecDeque<(usize, usize)> = VecDeque::new();
            q.push_back((sx, sy));
            while !q.is_empty() {
                //debug!(q);
                //debug!(visited);
                let (x, y) = q.pop_front().unwrap();
                if visited[x][y] == true {
                    continue;
                }
                //debug!(white);
                visited[x][y] = true;
                if s[x][y] == '.' {
                    ans += 1;
                    white = false;
                } else {
                    white = true;
                }
                for i in 0..4 {
                    let mut nx = x as i32;
                    let mut ny = y as i32;
                    nx += dx[i];
                    ny += dy[i];
                    if nx >= 0 && nx < h as i32 && ny >= 0 && ny < w as i32 {
                        if visited[nx as usize][ny as usize] {
                            continue;
                        }
                        if white {
                            if s[nx as usize][ny as usize] == '.' {
                                //debug!(nx);
                                //debug!(ny);
                                q.push_back((nx as usize, ny as usize));
                            }
                        } else {
                            if s[nx as usize][ny as usize] == '#' {
                                q.push_back((nx as usize, ny as usize));
                            }
                        }
                    }
                }
                /*
                if white {
                    white = false;
                } else {
                    white = true;
                }*/
            }
            //debug!(ans);
        }
    }
    println!("{}", ans);
}