Leetcode 9 Palindrome number Solution in Java | Hindi Coding Community

 

Given an integer x, return true if x is palindrome integer.

An integer is a palindrome when it reads the same backward as forward.

• For example, 121 is a palindrome while 123 is not.

 

Example 1:

Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.

Example 2:

Input: x = -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.

Example 3:

Input: x = 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

 

Constraints:

• -231 <= x <= 231 - 1

 

Follow up: Could you solve it without converting the integer to a string?

Java Code :

class Solution {

//finding reverse of the number using recursion

int rev(int n,int s){

if(n==0) return s;

int sum=s*10+n%10;

return rev(n/10,sum);

}

public boolean isPalindrome(int x) {

if(x<0) return false;

if(rev(x,0)==x) return true;

//if the reverse of the number is

//equal to the number returm true

else return false;

}

}