This is an open book, open notes, and open computer test. If you get stuck, talk to Jeff Ondich, but please don't talk to anyone else (not even Justin Thomson or the lab assistants) about the exam.

The first several problems refer to the printwords.cpp program you used as a starting point for your first programming assignment. For each problem, start with the original copy of printwords.cpp.

1. (4 points) Remove the interface for CleanWord (that is, delete the line of code immediately preceding the main program). What error message do you get when you try to compile the resulting program? Explain why the absence of the interface causes the compiler to be confused.
   
   
2. (4 points) If you remove the ampersand (&) from the CleanWord interface, and then compile and run the program, what happens? (You need to remove the ampersand in both places it appears--above main and down where CleanWord is defined.) Explain why the removal of the ampersand has this effect.
   
   
3. (9 points) Modify CleanWord so a hyphen at the beginning or end of the word is removed, while hyphens appearing in the middle of the word are retained. For example, "pre-eminent" would be unchanged by CleanWord, but "pre-" or "-pre" would be changed to "pre".
   
   
4. (10 points) Modify the main program to print the words in reverse order. Here's an outline of the strategy you should use:
   • Declare an array of enough strings to hold all the words in whatever file you intend to use to test your program. Something like "string theWords[1000];".
   • In the input loop, don't print the cleaned words. Instead, store each word in an entry of the array. You will need an integer variable to keep track of the index of the new word in the array.
   • After the input loop, write another loop starting at the end of the array and moving towards the beginning.
   
   
   
5. (2 points) What is dangerous about the strategy in the previous problem?
   
   
6. (2 points) Please direct me to an interesting or amusing web site.
   
   
7. (10 points) Consider the following implementation of IsPalindrome.

   
   	bool IsPalindrome( const string& s )
   	{
   		int left = 0;
   		int right = s.length() - 1;
   
   		while( left < right )
   		{
   			if( tolower( s[left] )  !=  tolower( s[right] ) )
   				return( false );
   			else
   				return( true );
   		}
   	}
   

   • If you try compiling this function along with a suitable main program, the compiler will give you a warning. What is the warning? What does it mean? How can you fix it?
   • Even if you ignore or fix the warning, this function does not work properly. What's wrong with it? For what kinds of strings does it return true? How can you fix the problem?
   
   
   
8. (5 points) Write a one-paragraph biography of one of the following people: Charles Babbage, Grace Hopper, or John Mauchly.