valid-sudoku

/ ** 
* IS Sudoku the Determine IF A Valid, ACCORDING to:. - Sudoku Puzzles of The Rules 
'.'. * Could Board of The Sudoku Partially Filled BE, empty cells are Filled with WHERE The Character 
* Partially Filled Sudoku Which IS A Valid. 
* 
* determined according to the following rules only if the number of valid: 
* number plate may only partially filled, empty cells wherein fill characters. "." Empty cell is used. Instead. 
* A number of partially filled alone is effective. 
* /

Analysis:
* The purpose of this question means that this number alone is valid, returns to true, false.
* There are three cases is not true, returns false:
* The first: each line cycle, if the same number appeared not established, encounter . skip
* the second: each column cycle, if the same number appeared not established encountered skip.
* third: the cycle every little squares, if the same number appears not established, the case to. skip (this cycle need to look at ways the law)

java.util.HashSet Import; 
Import java.util.Set; 

/ ** 
 * the Determine IF IS A Sudoku! Valid, ACCORDING to:. Sudoku Puzzles - at The Rules 
 * at The Sudoku Board could BE Partially Filled, the WHERE Filled with empty cells are at The '.'. character 
 * partially filled Sudoku which IS A valid. 
 * 
 * only determines the number is valid according to the following rules: 
 . "" * number plate may only partially filled, empty cells wherein fill characters. Empty cell is used. Instead. 
 * A number of partially filled alone is effective. 
 * 
 * Resolution: 
 * The purpose of this question means that this number alone is valid, returns to true, false. 
 * There are three cases is not true, returns false: 
 * The first: each line cycle, if the same number appeared not established, encounter skip. 
 * the second: each column cycle, if the same number appeared not established encountered skip. 
 * third: the cycle every little squares, if the same number appeared not established encountered. skip (this cycle need to look at ways the law) 
 * /

public class Main40 {
    public static void main(String[] args) {
        char[][] board = {
                {'.','.','4','.','.','.','6','3','.'},
                {'.','.','.','.','.','.','.','.','.'},
                {'5','.','.','.','.','.','.','9','.'},
                {'.','.','.','5','6','.','.','.','.'},
                {'4','.','3','.','.','.','.','.','.'},
                {'.','.','.','7','.','.','.','.','.'},
                {'.','.','.','1','.','.','.','.','.'},
                {'.','.','.','.','.','.','.','.','.'},
                {'.','.','.','.','.','.','.','.','.'}
        };
        System.out.println(Main40.isValidSudoku(board));
    }

    public static boolean isValidSudoku(char[][] board) {
        Set<Character> set = new HashSet<>();
        // 第一种情况：
        for (int i=0;i<board.length;i++) {
            for (int j=0;j<board[i].length;j++) {
                if (board[i][j] == '.') {
                    continue;
                }
                if (!set.contains(board[i][j])) {
                    set.add(board[i][j]);
                }else{
                    return false;
                }
            }
            set.clear();
        }
        // 第二种情况：
        for (int j=0;j<board[0].length;j++) {
            for (int i=0;i<board.length;i++) {
                if (board[i][j] == '.') {
                    continue;
                }
                if (!set.contains(board[i][j])) {
                    set.add(board[i][j]);
                }else{
                    return false;
                }
            }
            set.clear();
        }
        // 第三种情况：
        for (int k=0;k<board.length;k++) {
            for (int i=k/3*3;i<k/3*3+3;i++) {
                for (int j=k%3*3;j<k%3*3+3;j++) {
                    if (board[i][j] == '.') {
                        continue;
                    }
                    if (!set.contains(board[i][j])) {
                        set.add(board[i][j]);
                    }else{
                        return false;
                    }
                }
            }
            set.clear();
        }
        return true;
    }
}