题目：

题解：

class Solution {public boolean isValidSudoku(char[][] board) {int[][] rows = new int[9][9];int[][] columns = new int[9][9];int[][][] subboxes = new int[3][3][9];for (int i = 0; i < 9; i++) {for (int j = 0; j < 9; j++) {char c = board[i][j];if (c != '.') {int index = c - '0' - 1;rows[i][index]++;columns[j][index]++;subboxes[i / 3][j / 3][index]++;if (rows[i][index] > 1 || columns[j][index] > 1 || subboxes[i / 3][j / 3][index] > 1) {return false;}}}}return true;}
}