B. Strings and Character Arrays A C++ string and an array of characters have similar behavior and can be similarly processed. In fact, a C++ string is implemented as an array in the libraries, but there are some differences as a string is an object (containing member variables and member functions) while a character array (or c-string) is simply an array of characters. To show how we can process a character array (also called a c-string) and see some of these differences, let us write a program that reverses a user-entered string once character at a time into a c-string and then compares the two to see if they are the same, meaning that the user-entered word is a palindrome. Use the following partial program as a start and complete the following three commented portions: You can create the reverse c-string of the original string by processing the string in the usual manner (i.e., using a for loop to the end of the string) and then copying letter-by-letter, starting with the last letter of the regular string being assigned to the first letter of the character array. Inside the loop, this can be done with a simple assignment statement: assigning the letter from the string, starting with the last letter given by the rev variable (that has already been initialized to be the last letter of the string for you) to the first letter in the character array (the control variable i in the for loop). Then, be sure to decrement the rev variable so that it points to the next to last character in the string, and so forth. All c-strings must have a null terminator '\0' appended as the last character to make sure they work properly. Assign the null terminator to index following the last character copied from the string. Since we now have the original string and its reverse, fill in the if statement to perform a simple comparison of the original string and the reversed c- string to see if the string is a palindrome. Unfortunately, strings and c-strings are not directly comparable. To compare them, we must first convert the original string to a c-string using c_str () with the dot operator (e.g., for a string str, this can be done with str.c_str (). #include #include using namespace std; int main() { } string my_str; char reverse[21]; int i, rev; cout < > my_str; rev = my_str.length () - 1; // create the reverse c-string of the original string // assign null character to last character in c-string if ( // write Boolean condition to compare c-strings) { cout < < my_str < < " is a palindrome" < < endl; } else { } cout