Check if a number is Palindrome
- Shreyas Naphad
- May 8, 2024
- 1 min read
Updated: Jun 5, 2024
In this article, we will understand what a palindrome is and how to identify whether a number is a palindrome or not.
So in simple words, a palindrome number is a number that appears to be the same irrespective of whether you read it from the beginning or the end. For example: 1221, 2222, and 3443 are palindrome numbers
Problem Statement: Given an integer N, write a program to identify whether the number is a palindrome or not.
Example:
1) N = 121
Output: Palindrome
2) N = 100
Output: Not a Palindrome
The C++ Code to solve this problem is as follows:
Explanation:
· N is our input number which we pass to checkPalindrome() function.
· In this function we extract every digit of N starting from the last digit to the first digit and every digit extracted gets stored in X.
· Now once N is exhausted, X will be the reverse of N and if X is still equal to N then it means that the number is palindrome.
Time Complexity:
The time complexity is O(log10N + 1) where N is the input number. The time complexity is based on the number of digits in N and the worst case could be when N is a multiple of 10. Since inside the while loop, we are dividing N by 10 until N is 0, we have to take log10N iterations.
Space Complexity:
Since we are not taking any additional memory, the space complexity is O(1).
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