问题描写叙述：

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.



代码：

public class Valid_Sudoku {  //java

    public boolean isValidSudoku(char[][] board) {

        int size = 9;
        int [] member = new int[size];   //record if is occur; 

        //valid row
        for(int i = 0; i < 9; i++){

            for(int k = 0; k < 9; k++)
                member[k] = 0;
            for(int j = 0; j < 9; j++){
                if(board[i][j] == '.')
                    continue;
                int pos = board[i][j]-'0';
                if(member[pos-1] == 1)
                    return false;
                else member[pos-1] = 1;
            }
        }

        //valid col
        for(int i = 0; i < 9; i++){
            for(int k = 0; k < 9; k++)
                member[k] = 0;
            for(int j = 0; j < 9; j++){
                if(board[j][i] == '.')
                    continue;
                int pos = board[j][i]-'0';
                if(member[pos-1] == 1)
                    return false;
                else member[pos-1] = 1;
            }
        }

        //valid cube
        for(int ibegin = 0; ibegin < 9; ibegin = ibegin+3){
            for(int jbegin = 0; jbegin < 9; jbegin = jbegin+3){
                for(int k = 0; k < 9; k++)
                    member[k] = 0;
                for(int i = ibegin; i < ibegin+3; i++){
                    for(int j = jbegin; j < jbegin+3; j++){
                        if(board[i][j] == '.')
                            continue;
                        int pos = board[i][j]-'0';
                        if(member[pos-1] == 1)
                            return false;
                        else member[pos-1] = 1;
                    }
                }
            }
        }
        return true;
    }

    public static void main(String [] args){
        String[] boardStr = {"......5..",
                             ".........",
                             ".........",
                             "93..2.4..",
                             "..7...3..",
                             ".........",
                             "...34....",
                             ".....3...",
                             ".....52.."};
        char [][] board = new char [9][9];
        for(int i =0; i< boardStr.length; i++){
            for(int j = 0; j<boardStr[i].length(); j++){
                board[i][j] = boardStr[i].charAt(j);
            }
        }

        Valid_Sudoku vs = new Valid_Sudoku();
        System.out.println(vs.isValidSudoku(board));
    }
}