////////////////////////////////////////////////////////////////////////////////

// Author: Julie Petrusa (991339)                                             //

// Due date: February 12, 2002                                                //

// This program inputs a string of characters. Capitalization, punctuation,   //

// and spacing are ignored. The function Palindrome returns true if the       //

// string is a palindrome, and false if it is not. A palindrome is a word or  //

// a phrase whose letters read the same forward or backward.                  //

// Known bugs: none                                                           //

////////////////////////////////////////////////////////////////////////////////

#include <iostream.h>      // needed in order to do I/O

#include <stdlib.h>        // for system("PAUSE")

#include <ctype.h>         // for islower(), isupper(), tolower()



bool palindrome(char text[])

   {

   int length = strlen(text);    // get length of string

   int front = 0;                // initialize counter for front half

   int rear = length-1;          // initialize counter for rear half

   while (front < rear)          // stop when front has checked half the string

      {

      while (!islower(text[front]))                // while not small letter

         {                                         // in front half

         if (isupper(text[front]))                 // if capital letter

            text[front] = tolower(text[front]);    // change to small letter

         else                                      // else ignore punctuation

            front++;

         }

      while (!islower(text[rear]))                 // while not small letter

         {                                         // in rear half

         if (isupper(text[rear]))                  // if capital letter

            text[rear] = tolower(text[rear]);      // change to small letter

         else                                      // else ignore punctuation

            rear--;

         }

      if (text[front] != text[rear])   // if front is not equal to rear

         return false;                 // exit function returning false

      front++;                         // increment front

      rear--;                          // decrement rear

      }

   return true;                        // exit function returning true

   }



int main()

   {

   cout << "\n\nAuthor: Julie Petrusa (991339)\n";  // display banner

   cout << "Due date: February 12, 2002\n";

   cout << "This program inputs a string of characters. Capitalization, ";

   cout << "punctuation, and\nspacing are ignored. The function Palindrome ";

   cout << "returns true if the string is a\npalindrome, and false if it is ";

   cout << "not. A palindrome is a word or a phrase whose\nletters read the ";

   cout << "same forward or backward.\n";

   cout << "\n\nChoose one of the following options:\n";  // display options

   cout << "   1 --> Enter a palindrome\n";

   cout << "   2 --> Exit the program\n";

   cout << "Answer: ";

   int answer;

   cin >> answer;

   switch (answer)

      {

      case 1:

         cout << "\n\nPalindrome: ";

         char text[100];

         cin.setf(ios::skipws);  // ignore spacing

         cin.ignore(2, '\n');

         cin.get(text, 100);

         if (palindrome(text))

            cout << "\n\nThat is a palindrome!\n";

         else

            cout << "\n\nThat is NOT a palindrome!\n";

         break;

      }

   cout << "\n\n";

   system("PAUSE");  // terminate

   return 0;

   }  // end Palindromes