数组之8.4

/* 修改前一个问题的identity_matrix函数，他可以对数组进行扩展，
 * 从而能够接受任意大小的矩阵参数。函数的第一个参数应该是一个整型
 * 指针，你需要第二个参数用于指定矩阵的大小。
 */

 

/*
 * The storage order of the array elements allows a pointer to an
 * integer to be walked sequentially through the elements.Separate
 * counters keep track of the row and column, using the size argument
 * provided. Note that there is no way to check whether the matrix is
 * actually the size indicated by the second augrment.
 */

/* Test a square matrix to see if it is an identity matrix. */

#define FALSE    0
#define TRUE    1

int identity_matrix( int *matrix, int size )
{
    int row;
    int column;

    /* Go through each of the matrix elements */
    for( row=0; row<size; row+=1 )
    {
        for( column=0; column<size; column+=1 )
        {
        
            if( *matrix++ != ( row == column ) )    //?

                    return FALSE;
        }
    }
    
    return TRUE;
}