7.12 (card shuffling and dealing)
modify the c program in fig. 7.24 so that the card-dealing function deals a five-card poker hand. then write the following additional functions:

determine whether the hand contains a pair.
determine whether the hand contains two pairs.
determine whether the hand contains three of a kind (e.g., three jacks).
determine whether the hand contains four of a kind (e.g., four aces).
determine whether the hand contains a flush (i.e., all five cards of the same suit).
determine whether the hand contains a straight (i.e., five cards of consecutive face values)