Valid Sudoku

Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.

The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

A partially filled sudoku which is valid.

Note:
A valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.

public class Solution {    public boolean isValidSudoku(char[][] board) {        for(int i=0;i<9;i++){if(!isNineValid(board[i])){return false;}/** 竖直 */char[] tem=new char[9];for(int i1=0;i1<9;i1++){tem[i1]=board[i1][i];}if(!isNineValid(tem)){return false;}/** 方块 */int xx=i/3*3,yy=i%3*3;for(int i1=0;i1<9;i1++){tem[i1]=board[xx+i1/3][yy+i1%3];}if(!isNineValid(tem)){return false;}}        return true;    }    boolean isNineValid(char[] target){int[] flag=new int[9];for(char i:target){if(i=='.')continue;flag[i-'1']++;}for(int i:flag){if(i>1)return false;}return true;}}