[프로그래머스 | 자바스크립트] 안전지대

솔루션

function solution(board) {
  const isBombNearby = (r, c) => {
    const nearby = [
      [-1, -1],
      [-1, 0],
      [-1, 1],
      [0, -1],
      [0, 1],
      [1, -1],
      [1, 0],
      [1, 1],
    ];

    const isInBoard = (r, c) =>
      r >= 0 && r < board.length && c >= 0 && c < board.length;

    return nearby.some(
      ([dR, dC]) => isInBoard(r + dR, c + dC) && board[r + dR][c + dC] === 1
    );
  };

  let answer = 0;

  for (let r = 0; r < board.length; r++) {
    for (let c = 0; c < board.length; c++) {
      if (board[r][c] !== 1 && !isBombNearby(r, c)) answer += 1;
    }
  }
  console.log(answer);

  return answer;
}

solution([
  [0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0],
  [0, 0, 1, 0, 0],
  [0, 0, 0, 0, 0],
]);
solution([
  [0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0],
  [0, 0, 0, 0, 0],
  [0, 0, 1, 1, 0],
  [0, 0, 0, 0, 0],
]);
solution([
  [1, 1, 1, 1, 1, 1],
  [1, 1, 1, 1, 1, 1],
  [1, 1, 1, 1, 1, 1],
  [1, 1, 1, 1, 1, 1],
  [1, 1, 1, 1, 1, 1],
  [1, 1, 1, 1, 1, 1],
]);

 

솔루션

function solution2(board) {
  let outside = [
    [-1, 0],
    [-1, -1],
    [-1, 1],
    [0, -1],
    [0, 1],
    [1, 0],
    [1, -1],
    [1, 1],
  ];
  
  let answer = 0;

  board.forEach((row, y, self) =>
    row.forEach((it, x) => {
      if (it === 1) return false;
      return outside.some(([oy, ox]) => !!self[oy + y]?.[ox + x])
        ? false
        : answer++;
    })
  );
  console.log(answer);

  return answer;
}