check a string is palindrome or not

1// Check whether the string is a palindrome or not.
2#include <bits/stdc++.h>
3
4using namespace std;
5
6int main(){
7    string s;
8    cin >> s;
9    
10    int l = 0;
11    int h = s.length()-1;
12
13    while(h > l){
14        if(s[l++] != s[h--]){
15            cout << "Not a palindrome" << endl;
16            return 0;
17        }
18    }
19    cout << "Is a palindrome" << endl;
20    return 0;
21
22}

1def palindrome_check(string):
2    string = list(string)
3    tmp = []
4    #remove any spaces
5    for x in range(0, len(string)):
6        if(string[x] != " "):
7            tmp.append(string[x].lower())
8    
9            
10    #now reverse the string
11    array1 = []
12    i = 0
13    j = len(tmp)-1
14
15    while(i < len(tmp)):
16        array1.append(tmp[j])
17        i += 1
18        j -= 1
19
20    #check if array1 is equal to the string
21    counter = 0
22    for x in range(0, len(tmp)):
23        if(tmp[x] == array1[x]):
24            counter += 1
25
26    #if the counter is equal to the length of the string then the word
27    #is the same
28    if(counter == len(tmp)):
29        return True
30    
31    return False

1#include <iostream>
2using namespace std;
3 
4// Iterative function to check if given string is a palindrome or not
5bool isPalindrome(string str)
6{
7    int low = 0;
8    int high = str.length() - 1;
9 
10    while (low < high)
11    {
12        // if mismatch happens
13        if (str[low] != str[high])
14            return false;
15 
16        low++;
17        high--;
18    }
19 
20    return true;
21}
22 
23int main()
24{
25    string str = "XYXYX";
26 
27    if (isPalindrome(str))
28        cout << "Palindrome";
29    else
30        cout << "Not Palindrome";
31 
32    return 0;
33}
34

1#include <stdio.h>
2#include <string.h>
3int main()
4{
5
6     char str[80];
7     int length;
8     printf("\nEnter a string to check if it's a palindrome: ");
9     scanf("%s", str);     // string input
10     length = strlen(str); // finding the string length
11     int i, j, count;
12     for (i = 0, j = length - 1, count = 0; i < length; i++, j--)
13     {
14          // matching string first character with the string last character
15          if (str[i] == str[j])
16          {
17               count++; // if character match, increasing count by one.
18          }
19     }
20     if (count == length) // if count == length, then the string is a palindrome.
21     {
22          printf("'%s' is a palindrome.\n", str);
23     }
24     else // otherwise the string is not a palindrome.
25     {
26          printf("'%s' is not a palindrome.\n", str);
27     }
28     return 0;
29}

1#include <iostream>
2#include <string>
3#include <unordered_set>
4using namespace std;
5
6// expand in both directions of low and high to find all palindromes
7void expand(string str, int low, int high, auto &set)
8{
9	// run till str[low.high] is a palindrome
10	while (low >= 0 && high < str.length()
11			&& str[low] == str[high])
12	{
13		// push all palindromes into the set
14		set.insert(str.substr(low, high - low + 1));
15
16		// expand in both directions
17		low--, high++;
18	}
19}
20
21// Function to find all unique palindromic substrings of given string
22void allPalindromicSubstrings(string str)
23{
24	// create an empty set to store all unique palindromic substrings
25	unordered_set<string> set;
26
27	for (int i = 0; i < str.length(); i++)
28	{
29		// find all odd length palindrome with str[i] as mid point
30		expand(str, i, i, set);
31
32		// find all even length palindrome with str[i] and str[i+1] as
33		// its mid points
34		expand(str, i, i + 1, set);
35	}
36
37	// print all unique palindromic substrings
38	for (auto i : set)
39		cout << i << " ";
40}
41
42int main()
43{
44	string str = "google";
45
46	allPalindromicSubstrings(str);
47
48	return 0;
49}

1function isPalindrome(str) {
2  str = str.toLowerCase();
3  return str === str.split("").reverse().join("");
4}