Table of Contents
Problem Statement
Palindrome Number LeetCode Solution says that –
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 while123
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.
Constraints:
-2
31<= x <= 2
31- 1
Algorithm:
Idea:
- In order to find the Palindrome Number. First, we will focus on the palindrome if the given number is equal to the reverse of the given number then we can say that the number is a palindrome and return True else return False.
Approach:
- First, we will make one variable Total, and initially, the value of the variable will be zero then we will use the condition that the given number should be greater than zero then we will find the modulo of that number and add that number into the total by using total = total*10+number and at last, we will update the number by number // 10.
- At last, we will return the Total.
Code:
Palindrome Number Python LeetCode Solution:
class Solution: def isPalindrome(self, x: int) -> bool: total = 0 k = x while(x > 0): b = x%10 total = total*10+b x = x//10 if total == k: return True else: return False
Palindrome Number Java LeetCode Solution:
class Solution { public boolean isPalindrome(int x) { int total = 0; int k = x; while(x > 0){ int b = x%10; total = total*10 + b; x = x/10; } if(total == k) return true; return false; } }
Complexity Analysis :
Time complexity:
O(N).
Space complexity:
O(n).
Similar Problem: https://tutorialcup.com/interview/string/shortest-palindrome.htm