how to check whether a string is palindrome or not code example

Example 1: check if a string is palindrome cpp

// Check whether the string is a palindrome or not.
#include 

using namespace std;

int main(){
    string s;
    cin >> s;
    
    int l = 0;
    int h = s.length()-1;

    while(h > l){
        if(s[l++] != s[h--]){
            cout << "Not a palindrome" << endl;
            return 0;
        }
    }
    cout << "Is a palindrome" << endl;
    return 0;

}

Example 2: Write a function that tests whether a string is a palindrome

def palindrome_check(string):
    string = list(string)
    tmp = []
    #remove any spaces
    for x in range(0, len(string)):
        if(string[x] != " "):
            tmp.append(string[x].lower())
    
            
    #now reverse the string
    array1 = []
    i = 0
    j = len(tmp)-1

    while(i < len(tmp)):
        array1.append(tmp[j])
        i += 1
        j -= 1

    #check if array1 is equal to the string
    counter = 0
    for x in range(0, len(tmp)):
        if(tmp[x] == array1[x]):
            counter += 1

    #if the counter is equal to the length of the string then the word
    #is the same
    if(counter == len(tmp)):
        return True
    
    return False

Example 3: reads the string in then determines if the string is a palindrome.

#include 
using namespace std;
 
// Recursive function to check if str[low..high] is a palindrome or not
bool isPalindrome(string str, int low, int high)
{
    // base case
    if (low >= high)
        return true;
 
    // return false if mismatch happens
    if (str[low] != str[high])
        return false;
 
    // move to next the pair
    return isPalindrome(str, low + 1, high - 1);
}
 
int main()
{
    string str = "XYBYBYX";
    int len = str.length();
 
    if (isPalindrome(str, 0, len - 1))
        cout << "Palindrome";
    else
        cout << "Not Palindrome";
 
    return 0;
}

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