Write a routine which will accept a character string as input and determine if it is in the form of X l'Cl| Y where X is a string consisting of the letters 'A' and 'B' and Y is the reverse of X. (That is if X 'ABBAB' then Y BABBA'. At each point in the routine you may read only the next character of the string. The C' is the delimiter for 'X' and 'Y') IV. Given a doubly linked list write a routine which will travel through the list adding 10 to every node whose information field is an even number and then travel backwards thru the list subtracting 4 from every node whose information field contains an odd number. V