拿到矩形的外圈
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
if (i == 0 || i == row - 1 || j == 0 || j == col - 1) {
if (board[i][j] == 'O') {
deque.offer(new Integer[]{i, j});
isVisited[i][j] = true;
}
}
}
}
for (int i = 0; i < row; i++) {
for (int j = 0; j < col; j++) {
if (i == 0 || i == row - 1 || j == 0 || j == col - 1) {
if (board[i][j] == 'O') {
deque.offer(new Integer[]{i, j});
isVisited[i][j] = true;
}
}
}
}