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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)


import java.util.AbstractMap;
import java.util.Queue;
import java.util.Scanner;
import java.util.concurrent.ArrayBlockingQueue;

public class Main {

     static Scanner scanner;

     public static void main(String[] args) {
         scanner = new Scanner(System.in);

         int H=gi();
         int W=gi();
         char[][] cs=new char[H][W];
         boolean[][] fd=new boolean[H][W];

         long ans =0;
         for (int i=0; i<H;i++) {
             String s=gs();
             for (int j=0; j<W;j++) {
                  cs[i][j]=s.charAt(j);
             }
         }

         Queue<Pair<Integer,Integer>> q=new ArrayBlockingQueue<Pair<Integer,Integer>>(H*W);
         for (int i=0; i<H;i++) {
             for (int j=0; j<W;j++) {
                 if (cs[i][j]=='#' && fd[i][j]==false) {
                     if (fd[i][j]==false) {
                         boolean[][] f=new boolean[H][W];
                         q.add(new Pair<Integer,Integer>(i,j));
                         f[i][j]=true;
                         fd[i][j]=true;
                         int c=1;
                         int tmp=0;
                         while(!q.isEmpty()) {
                             Pair<Integer,Integer> p=q.poll();
                             int h=p.getKey();
                             int w=p.getValue();
                             if(h>0 && f[h-1][w]==false && cs[h-1][w]!=cs[h][w]) {
                                 q.add(new Pair<Integer,Integer>(h-1,w));
                                 if(cs[h-1][w]=='.') {
                                	 tmp++;
                                 } else {
                                	 c++;
                                 }
                                 f[h-1][w]=true;
                                 fd[h-1][w]=true;
                             }
                             if(w>0 && f[h][w-1]==false && cs[h][w-1]!=cs[h][w]) {
                                 q.add(new Pair<Integer,Integer>(h,w-1));
                                 if(cs[h][w-1]=='.') {
                                	 tmp++;
                                 } else {
                                	 c++;
                                 }
                                 f[h][w-1]=true;
                                 fd[h][w-1]=true;
                             }
                             if(h+1<H  && f[h+1][w]==false && cs[h+1][w]!=cs[h][w]) {
                                 q.add(new Pair<Integer,Integer>(h+1,w));
                                 if(cs[h+1][w]=='.') {
                                	 tmp++;
                                 } else {
                                	 c++;
                                 }
                                 f[h+1][w]=true;
                                 fd[h+1][w]=true;
                             }
                             if(w+1<W && f[h][w+1]==false && cs[h][w+1]!=cs[h][w]) {
                                 q.add(new Pair<Integer,Integer>(h,w+1));
                                 if(cs[h][w+1]=='.') {
                                	 tmp++;
                                 } else {
                                	 c++;
                                 }
                                 f[h][w+1]=true;
                                 fd[h][w+1]=true;
                             }
                         }
                         ans+=tmp*c;
                     }
                 }
             }
         }

         System.out.println(ans);

     }

     public static class Pair<K, V> extends AbstractMap.SimpleEntry<K, V> implements Comparable<Pair<K, V>> {
            /** serialVersionUID. */
            private static final long serialVersionUID = 6411527075103472113L;

            public Pair(final K key, final V value) {
                super(key, value);
            }

            @Override
            public int compareTo(Pair<K, V> o) {

                Comparable key = (Comparable)this.getKey();
                Comparable key2 = (Comparable)o.getKey();

                return key.compareTo(key2);
            }

        }
     // 文字列として入力を取得
     public static String gs() {
          return scanner.next();
     }

     // intとして入力を取得
     public static int gi() {
          return Integer.parseInt(scanner.next());
     }

     // longとして入力を取得
     public static long gl() {
          return Long.parseLong(scanner.next());
     }

     // doubleとして入力を取得
     public static double gd() {
          return Double.parseDouble(scanner.next());
     }
}