//check a 9*9 sudoku //Returns true if this grid is legal. A grid is legal if no row, column, or // 3x3 block contains a repeated 1, 2, 3, 4, 5, 6,...

//check a 9*9 sudoku

//Returns true if this grid is legal. A grid is legal if no row, column, or

// 3x3 block contains a repeated 1, 2, 3, 4, 5, 6, 7, 8, or 9.

// *** I Have already done to check row, and column but I have no idea how to check if it has legal 3*3 block in 9*9 sudoku

// Only need help to do the last part, check the block

public boolean isLegal()

{

// Check every row. If you find an illegal row, return false.

for(int i=0; i<values.length; i++)

  {

    for(int j=0; j<values[0].length; j++)

    {

    int num = values[i][j];

    for(int col=j+1; col<values[0].length; col++)

    {

    if(num == values[i][col])

    {

    return false;

    }

    }

    } 

  }

// Check every column. If you find an illegal column, return false.

for(int i=0; i<values.length; i++)

  {

    for(int j=0; j<values[0].length; j++)

    {

    int num = values[i][j];

    for(int row=i+1; row<values.length; row++)

    {

    if(num == values[row][j])

    {

    return false;

    }

    }

    } 

  }

// Check every block. If you find an illegal block, return false.

// need help!