[JS][백준]1018_체스판 다시 칠하기

문제 번호

1018번: 체스판 다시 칠하기

 

 

알고리즘 분류

브루트포스 

 

문제 풀이

 정상적으로 칠해진 8*8 크기의 체스판 2개를 미리 생성했다. 검은색부터 칠해진것 하나, 흰색부터 칠해진것 하나.

let white = ['WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW']
let black = ['BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB']

 

 문제에서 주어진 체스판을 (0,0) 좌표부터 (M - 8, N - 8)좌표 까지 탐색하면서 8*8크기로 때어내어 정상인 체스판과 비교했다. 

for (let i = 0; i <= N - 8; i++) {
  for (let j = 0; j <= M - 8; j++) {
    check(j, i);
  }
}

function check(x, y) {
  let checkWhite = 0;
  let checkBlack = 0;

  for (let i = y; i < y + 8; i++) {
    for (let j = x; j < x + 8; j++) {      
      if (board[i][j] !== white[i-y][j-x])
        checkWhite++;
      if (board[i][j] !== black[i-y][j-x])
        checkBlack++;
    }
  }

  let min = checkBlack < checkWhite ? checkBlack : checkWhite;
  
  if (min < answer)
    answer = min;
}

 

전체코드

const fs = require('fs');
let input = fs.readFileSync('/dev/stdin').toString().split('\n');

let NM = input.shift().split(' ');
let N = Number(NM.shift());
let M = Number(NM.shift());
let white = ['WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW']
let black = ['BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB', 'BWBWBWBW', 'WBWBWBWB']

let board = [];
for (let i = 0; i < N; i++) {
  board[i] = input.shift().split('');
}

let answer = 90;

for (let i = 0; i <= N - 8; i++) {
  for (let j = 0; j <= M - 8; j++) {
    check(j, i);
  }
}

function check(x, y) {
  let checkWhite = 0;
  let checkBlack = 0;

  for (let i = y; i < y + 8; i++) {
    for (let j = x; j < x + 8; j++) {      
      if (board[i][j] !== white[i-y][j-x])
        checkWhite++;
      if (board[i][j] !== black[i-y][j-x])
        checkBlack++;
    }
  }

  let min = checkBlack < checkWhite ? checkBlack : checkWhite;
  
  if (min < answer)
    answer = min;
}

console.log(answer);

특이사항