Question

Write a program that uses the function isPalindrome given in Example 6-6 (Palindrome). Test your program on the following strings:

madam, abba, 22, 67876, 444244, trymeuemyrt

Modify the function isPalindrome of Example 6-6 so that when determining whether a string is a palindrome, cases are ignored, that is, uppercase and lowercase letters are considered the same.

The isPalindrome function from Example 6-6 has been included below for your convenience.

bool isPalindrome(string str)
{
int length = str.length();
for (int i = 0; i < length / 2; i++) {
if (str[i] != str[length – 1 – i]) {
return false;
} // if
} // for loop
return true;
}// isPalindrome

Your program should print a message indicating if a string is a palindrome:

madam is a palindrome

Answer 1

The isPalindrome function is modified to test strings for being palindromes in a case-insensitive manner by converting them to lower case before comparison. The modified function is then tested with various strings to check for palindromes.

Step-by-step explanation:

A student is tasked with writing a program that can test if certain strings are palindromes. The provided isPalindrome function checks if a string reads the same forwards as backwards. To account for case insensitivity, we modify the function so that it compares characters in a case-insensitive manner by converting the string to a single case before the comparison loop.

Here is the modified version of the isPalindrome function:

bool isPalindrome(string str)
{
for (char &c : str) c = tolower(c); // Convert all characters to lowercase
int length = str.length();
for (int i = 0; i < length / 2; i++) {
if (str[i] != str[length – 1 – i]) {
return false;
}
}
return true;
}

When testing this function with strings such as 'madam', 'abba', '22', '67876', '444244', 'trymeuemyrt', it will now correctly identify palindromes regardless of the case of the letters.

Answer 2

Step-by-step explanation:

bool isPalindrome(string str)

{

int length = str.length();

for (int i = 0; i < length / 2; i++) {

if (str [i] != str [length – 1 – i]) {

return false;

}

}

cout << str << "is a palindrome";

return true;

}