/*
          Function: printCube
       Description: generate the Cube in array and print it
             Input: 
                    [array]: the array for store Cube's data ( enough to store the data, minimum array[n][n] )
                        [n]: the Cube size ( n > 0 )
            Output: 
            Return: 
            Others: 
                    if( n == 3 ) cube is:
                    { 
                        1   2   3

                        8   9   4

                        7   6   5
                    }              
 */
void printCube( int array[][N], int n )
{
    assert( 0 < n );

    //      i, j: index for array; 
    //  min, max: border index for assignment Cube data 
    //         m: data for Cube, add one every step;
    int i, j, min, max, m;

    /* generate Cube data in array */
    for( m = 1, min = 0, max = n - 1; max > min; max--, min++ )
    {
        for( i = min, j = min; j < max; j++ )
            array[i][j] = m++; // first step: generate row data form left to right ( min to max-1 )
        for( ; i < max; i++ )
            array[i][j] = m++; // second step: generate column data from top to bottom ( min to max-1 )
        for( ; j > min; j-- )
            array[i][j] = m++; // third step: generate row data from right to left ( max to min+1 )
        for( ; i > min; i-- )
            array[i][j] = m++; // fourth step: generate column data from bottom to top ( max to min+1 )
    }
    if( min == max ) array[min][max] = m++;

    /* print Cube */
    for( i = 0; i < n; i++ )
    {
        for( j = 0; j < n; j++ )
        {
            printf(" %4d ", array[i][j]);
        }
        printf("\n");
    }
}