please help with 2.2 in C

Card Games

A shuffle is an array of 52 pairs of integers. The first of the pair is the card type (0-13 representing Ace, 2, 3, .... King) and the second representing the suit (hearts, diamonds, clubs, spades). Thus a pair of numbers describes a unique card in the deck. For example, {6,3} would describe the Six of Clubs, and {13,1} would be the King of Hearts.

2.1 Shuffling

Write a function (void fill(shuffle[52][2])) to fill a shuffle with 52 random integer pairs, BUT, as with your playing cards, there must be exactly one of each pair in the shuffle.

2.2 Compact Data Representation

A hand is an array of seven unsigned chars. Each char represents one card. We use a four bit field in the char for each of the two numbers above: the four most significant bits [bits 7...4] represent the card number (1-13) and the lower four [bits 3...0] represent the suit.

Write functions to:

a) convert two integers (from a shuffle for example) into a char as above.

unsigned char convert(int card, int suit);

b) get the integer suit from a char.

int gsuit(unsigned char card);

c) get the integer card from a char.

int gcard(unsigned char card);

All functions must print a warning message and return CARD ERROR (already defined at top of file) if they get invalid input (such as suit > 4).

Write code which verifies these functions work properly and prints results.