Write a function that takes a string, s, as an input and determines whether or not it is a palindrome.

Note: A palindrome is a word, phrase, or sequence of characters that reads the same backward as forward.


  • 11 \leq s.length 2×105\leq 2 \times 10^5
  • The string s will contain English uppercase and lowercase letters, digits, and spaces.


Understand the problem

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Valid Palindrome


“abab” is a palindrome.





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Implement your solution in in the following coding playground. We have provided a useful code template in the other file that you may build on to solve this problem.

usercode >
import java.util.*;
public class Main{
public static boolean isPalindrome(String s) {
// Replace this placeholder return statement with your code
return false;
Valid Palindrome