public boolean checkRowCol(char[][] board, int index, boolean row) {
		boolean[] has = new boolean[9];
		for(int i = 0; i < 9; i ++) {
			char ch = (row ? board[index][i] : board[i][index]);
			if(ch != '.') {
				if(has[ch - '1']) return false;
				has[ch - '1'] = true;
			}
		}
		return true;
	}