Java program to check whether a string is a Palindrome
Given a string str, the task is to find whether the string is a palindrome or not in Java without using library methods.
Examples:
Input: str = “abba”
Output: YesInput: str = “geeks”
Output: No
Approach: Take two pointers i pointing to the start of the string and j pointing to the end of the string. Keep incrementing i and decrementing j while i < j and at every step check whether the characters at these pointers are same or not. If not then the string is not a palindrome else it is.
Below is the implementation of the above approach:
Java
// Java implementation of the approachpublic class GFG { // Function that returns true if // str is a palindrome static boolean isPalindrome(String str) { // Pointers pointing to the beginning // and the end of the string int i = 0, j = str.length() - 1; // While there are characters to compare while (i < j) { // If there is a mismatch if (str.charAt(i) != str.charAt(j)) return false; // Increment first pointer and // decrement the other i++; j--; } // Given string is a palindrome return true; } // Driver code public static void main(String[] args) { String str = "geeks"; if (isPalindrome(str)) System.out.print("Yes"); else System.out.print("No"); }} |
No
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.
In case you wish to attend live classes with experts, please refer DSA Live Classes for Working Professionals and Competitive Programming Live for Students.
