validSudoku

class Solution {
    public boolean rowCheck(char [][]board,int row,int col)
    {
        Set<Integer> set=new HashSet<Integer>();
        for(int i=0;i<9;i++)
        {
            if(board[row][i]=='.')
                continue;
            int temp=board[row][i]-'0';
            if(set.contains(temp))
                return false;
            set.add(temp);
        }
        return true;
    }
    public boolean colCheck(char [][]board,int row,int col)
    {
        Set<Integer> set=new HashSet<Integer>();
        for(int i=0;i<9;i++)
        {
            if(board[i][col]=='.')
                continue;
            int temp=board[i][col]-'0';
            if(set.contains(temp))
                return false;
            set.add(temp);
        }
        return true;
    }
    public boolean boxCheck(char [][]board,int row,int col)
    {
        Set<Integer> set=new HashSet<Integer>();
        for(int i=row;i<row+3;i++)
        {
            for(int j=col;j<col+3;j++)
            {
                if(board[i][j]=='.')
                    continue;
                int temp=board[i][j]-'0';
                if(set.contains(temp))
                return false;
                set.add(temp);
            }
        }
        return true;
    }
    
    public boolean isValid(char [][]board,int row,int col)
    {
        return rowCheck(board,row,col) & colCheck(board,row,col) & boxCheck(board,row-row%3,col-col%3);
    }
    public boolean isValidSudoku(char[][] board) {
        for(int i=0;i<9;i++)
        {
            for(int j=0;j<9;j++)
            {
                if(!isValid(board,i,j))
                    return false;
            }
        }
        return true;
    }
}