BOJ1018 체스판 다시 칠하기

https://www.acmicpc.net/problem/1018

1018번: 체스판 다시 칠하기

import java.util.*;
import java.io.*;
public class Main
{
    public static int calcStartBlack(String[][] map){
        int count=0;
        for(int i=0;i<8;i++){
            for(int j=0;j<8;j++){
                if(i%2==0){
                    if(j%2==0){
                        if(map[i][j].equals("B")) count++;
                        
                    }else{
                        if(map[i][j].equals("W")) count++;
                    }
                }else{
                    if(j%2==0){
                        if(map[i][j].equals("W")) count++;
                    }else{
                        if(map[i][j].equals("B")) count++;
                    }
                }
            }
            
        }
        
        return count;
    }
    public static int calcStartWhite(String[][] map){
        int count=0;
        for(int i=0;i<8;i++){
            for(int j=0;j<8;j++){
                if(i%2==0){
                    if(j%2==0){
                        if(map[i][j].equals("W")) count++;
                        
                    }else{
                        if(map[i][j].equals("B")) count++;
                    }
                }else{
                    if(j%2==0){
                        if(map[i][j].equals("B")) count++;
                    }else{
                        if(map[i][j].equals("W")) count++;
                    }
                }
            }
            
        }
        
        return count;

    }

	public static void main(String[] args) throws IOException {
            
	    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	    Scanner sc = new Scanner(System.in);
	    String[] input = br.readLine().split(" ");
	    int N  = Integer.valueOf(input[0]);
	    int M  = Integer.valueOf(input[1]);
	   
	    
	    String[][] map = new String[N][M];
	    
	    for(int i=0;i<N;i++){
	        map[i] = br.readLine().split("");
	    }
        
        int minCount=2501;
        for(int i =0;i<=N-8;i++){
            for(int j=0;j<=M-8;j++){
                String[][] chessMap = new String[8][8];
                for(int k=0;k<8;k++){
                    for(int l=0;l<8;l++){
                        chessMap[k][l]=map[i+k][j+l];
                    }
                }
                int tempCount=Math.min(calcStartWhite(chessMap),calcStartBlack(chessMap));
                if(minCount>tempCount) minCount=tempCount;
                
            }
        }
        System.out.println(minCount);

	}
}

import java.util.Scanner;

class Main
{
    private static int countDifferent(char[][] map, int starRow, int startColumn, String pattern) {
        int cnt = 0;
        for (int i = starRow; i < starRow + 8; i++)
            for (int j = startColumn; j < startColumn + 8; j++)
                if (map[i][j] != pattern.charAt((i + j) % 2))
                    cnt++;
        return cnt;
    }

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

        int N = sc.nextInt();
        int M = sc.nextInt();
        char[][] map = new char[N][M];
        for(int i = 0; i < N; i++) {
            String line = sc.next();
            map[i] = line.toCharArray();
        }

        int ans = N * M;
        for (int i = 0; i <= N - 8; i++)
            for (int j = 0; j <= M - 8; j++) {
                int countBW = countDifferent(map, i, j, "BW");
                int countWB = countDifferent(map, i, j,"WB");
                ans = Math.min(ans, Math.min(countBW, countWB));
            }
        System.out.println(ans);
    }
}