(Palindromes) A palindrome is a string that is spelled the same way forward and backward. Examples of palindromes include “radar” and “able was i ere i saw elba.” Write a recursive function testPalindrome that returns true if a string is a palindrome, and false otherwise. Note that like an array the square brackets ([]) operator can be used to iterate through the characters in a string.

Question

What will be an ideal response?

Answer 1

```
#include
#include
using namespace std;

bool testPalindrome( string, int, int );

int main()
{
string input;

// get sentence to test from user
cout << "Enter a sentence:\n";
getline( cin, input );

// Print whether or not sentence is palindrome
if ( testPalindrome( input, 0, input.length() - 1 ) )
cout << '\"' << string << "\" is a palindrome" << endl;
else
cout << '\"' << string << "\" is not a palindrome" << endl;
} // end main

// function to see if sentence is a palindrome
bool testPalindrome( string palindrome, int left, int right )
{
// test array to see if a palindrome
if ( left == right || left > right )
return true;
else if ( palindrome[ left ] != palindrome[ right ] )
return false;
else
return testPalindrome( palindrome, left + 1, right - 1 );
} // end function testPalindrome
```
Enter a sentence:
a man a plan a canal panama
"a man a plan a canal panama" is a palindrome
Enter a sentence:
c++ is fun
"c++ is fun" is not a palindrome