Assignment #4 – (100 points) Solution

$30.00

Description

Questions

1.(40points)Writeafunctionintcrypticcalculator(void*payload)

Where:

• If the first byte in payload is a character ’*’ representing the multiplication operation, you are to return the product of 3 short ints starting at bytes 3, 5 and 7.

• If the first byte in the payload is a character ’/’ representing division, you are to return the quotient when you divide int starting at byte 5 by short int starting at byte 3. If short int starting at byte 3 is 0, you are to return

0xBAD.

• If the first byte is neither ’*’ or ’/’, you are to return 0xBAD.

HINT: Cast payload to an appropriate appropriate structure. Byte 1 is at &payload, byte 3 is at &payload + 2, byte 5 is at &payload + 4 and so on.

2.(40points)Writeafunction:voidmymemcpy(void *dst, void *src, unsigned int num bytes) that copies num bytes from memory pointed

tobysrctomemorypointedtobydst.HINT:Loopnumbytestimesandcopy onecharatatimefromsrctodst.

3.(20 points)Writeafunction:void swapstrs(char*s1, char *s2) that swaps two character strings at s1 and s2. Assume both strings s1 and s2 to be of same length.