i CAN HELP U WITH DIFFERENCE OF UNION AND STRUCTURE:
wHEN U DECLARE VARIABLES IN A UNION ,THE MEMORY ALLOCATED TO A UNION IS OF THE SIZE OF MAXIMUM SIZE OF THE VARIABLE IN THE UNION AND NOT THE SUM OF THE SIZES OF VARIABLES....
Wheras in structure,the total memory allocated is the sum of the sizes of the variables....
Suppose u declare three variables of 2byte, 4byte ,and 8byte in union the memory allocated to union is of 8byte
u declare three variables of 2byte, 4byte ,and 8byte in Structure the memory allocated to structure is of 14byte.....